--- title: What is the plastic ring on my Signature portafilter holder for? description: What is the plastic ring on my Signature portafilter holder for? --- [![company logo](https://support.flairespresso.com/hs-fs/hubfs/flair_espresso_logo_2018-2.png?height=120&name=flair_espresso_logo_2018-2.png)](https://flairespresso.com) [Flair Help Center](https://support.flairespresso.com/knowledge) - [Go to flairespresso.com](https://flairespresso.com) - [Contact us](https://support.flairespresso.com/knowledge/kb-tickets/new) FAQs - [Account Information](https://support.flairespresso.com/knowledge/account-information) - [Account and Purchase History](https://support.flairespresso.com/knowledge/account-information#account-and-purchase-history) - [Managing Payments and Billing](https://support.flairespresso.com/knowledge/account-information#managing-payments-and-billing) - [Processing and Shipping Information](https://support.flairespresso.com/knowledge/account-information#processing-and-shipping-information) - [Promotions](https://support.flairespresso.com/knowledge/account-information#promotions) - [Returns and Warranty](https://support.flairespresso.com/knowledge/returns-and-warranty) - [Return Information](https://support.flairespresso.com/knowledge/returns-and-warranty#return-information) - [Warranty Policy](https://support.flairespresso.com/knowledge/returns-and-warranty#warranty-policy) - [Partners and Collaborators](https://support.flairespresso.com/knowledge/partners-and-collaborators) - [Before You Buy](https://support.flairespresso.com/knowledge/before-you-buy) - [Espresso 101](https://support.flairespresso.com/knowledge/before-you-buy#espresso-101) - [Flair FAQs](https://support.flairespresso.com/knowledge/before-you-buy#flair-faqs) - [The Flair 58 Family](https://support.flairespresso.com/knowledge/the-flair-58-family) - [Getting Started](https://support.flairespresso.com/knowledge/the-flair-58-family#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-flair-58-family#faqs) - [Recommendations](https://support.flairespresso.com/knowledge/the-flair-58-family#recommendations) - [The Flair 58+](https://support.flairespresso.com/knowledge/the-flair-58-family#the-flair-58) - [The PRO2](https://support.flairespresso.com/knowledge/the-pro2) - [Getting Started](https://support.flairespresso.com/knowledge/the-pro2#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-pro2#faqs) - [Recommendations](https://support.flairespresso.com/knowledge/the-pro2#recommendations) - [The Classic](https://support.flairespresso.com/knowledge/the-classic) - [Getting Started](https://support.flairespresso.com/knowledge/the-classic#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-classic#faqs) - [Recommendations](https://support.flairespresso.com/knowledge/the-classic#recommendations) - [The NEO Flex](https://support.flairespresso.com/knowledge/the-neo-flex) - [Getting Started](https://support.flairespresso.com/knowledge/the-neo-flex#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-neo-flex#faqs) - [Flow Control Portafilter](https://support.flairespresso.com/knowledge/the-neo-flex#flow-control-portafilter) - [Recommendations](https://support.flairespresso.com/knowledge/the-neo-flex#recommendations) - [The Royal Grinder](https://support.flairespresso.com/knowledge/the-royal-grinder) - [Getting Started](https://support.flairespresso.com/knowledge/the-royal-grinder#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-royal-grinder#faqs) - [The Signature](https://support.flairespresso.com/knowledge/the-signature) - [Getting Started](https://support.flairespresso.com/knowledge/the-signature#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-signature#faqs) - [Recommendations](https://support.flairespresso.com/knowledge/the-signature#recommendations) - [The NEO](https://support.flairespresso.com/knowledge/the-neo) - [Getting Started](https://support.flairespresso.com/knowledge/the-neo#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-neo#faqs) - [Flow Control Portafilter](https://support.flairespresso.com/knowledge/the-neo#flow-control-portafilter) - [Recommendations](https://support.flairespresso.com/knowledge/the-neo#recommendations) [Back to home](https://support.flairespresso.com/knowledge) 1. [Flair Help Center](https://support.flairespresso.com/knowledge) 2. [The Signature](https://support.flairespresso.com/knowledge/the-signature) 3. FAQs - [Account Information](https://support.flairespresso.com/knowledge/account-information) - [Account and Purchase History](https://support.flairespresso.com/knowledge/account-information#account-and-purchase-history) - [Managing Payments and Billing](https://support.flairespresso.com/knowledge/account-information#managing-payments-and-billing) - [Processing and Shipping Information](https://support.flairespresso.com/knowledge/account-information#processing-and-shipping-information) - [Promotions](https://support.flairespresso.com/knowledge/account-information#promotions) - [Returns and Warranty](https://support.flairespresso.com/knowledge/returns-and-warranty) - [Return Information](https://support.flairespresso.com/knowledge/returns-and-warranty#return-information) - [Warranty Policy](https://support.flairespresso.com/knowledge/returns-and-warranty#warranty-policy) - [Partners and Collaborators](https://support.flairespresso.com/knowledge/partners-and-collaborators) - [Before You Buy](https://support.flairespresso.com/knowledge/before-you-buy) - [Espresso 101](https://support.flairespresso.com/knowledge/before-you-buy#espresso-101) - [Flair FAQs](https://support.flairespresso.com/knowledge/before-you-buy#flair-faqs) - [The Flair 58 Family](https://support.flairespresso.com/knowledge/the-flair-58-family) - [Getting Started](https://support.flairespresso.com/knowledge/the-flair-58-family#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-flair-58-family#faqs) - [Recommendations](https://support.flairespresso.com/knowledge/the-flair-58-family#recommendations) - [The Flair 58+](https://support.flairespresso.com/knowledge/the-flair-58-family#the-flair-58) - [The PRO2](https://support.flairespresso.com/knowledge/the-pro2) - [Getting Started](https://support.flairespresso.com/knowledge/the-pro2#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-pro2#faqs) - [Recommendations](https://support.flairespresso.com/knowledge/the-pro2#recommendations) - [The Classic](https://support.flairespresso.com/knowledge/the-classic) - [Getting Started](https://support.flairespresso.com/knowledge/the-classic#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-classic#faqs) - [Recommendations](https://support.flairespresso.com/knowledge/the-classic#recommendations) - [The NEO Flex](https://support.flairespresso.com/knowledge/the-neo-flex) - [Getting Started](https://support.flairespresso.com/knowledge/the-neo-flex#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-neo-flex#faqs) - [Flow Control Portafilter](https://support.flairespresso.com/knowledge/the-neo-flex#flow-control-portafilter) - [Recommendations](https://support.flairespresso.com/knowledge/the-neo-flex#recommendations) - [The Royal Grinder](https://support.flairespresso.com/knowledge/the-royal-grinder) - [Getting Started](https://support.flairespresso.com/knowledge/the-royal-grinder#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-royal-grinder#faqs) - [The Signature](https://support.flairespresso.com/knowledge/the-signature) - [Getting Started](https://support.flairespresso.com/knowledge/the-signature#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-signature#faqs) - [Recommendations](https://support.flairespresso.com/knowledge/the-signature#recommendations) - [The NEO](https://support.flairespresso.com/knowledge/the-neo) - [Getting Started](https://support.flairespresso.com/knowledge/the-neo#getting-started) - [FAQs](https://support.flairespresso.com/knowledge/the-neo#faqs) - [Flow Control Portafilter](https://support.flairespresso.com/knowledge/the-neo#flow-control-portafilter) - [Recommendations](https://support.flairespresso.com/knowledge/the-neo#recommendations) # What is the plastic ring on my Signature portafilter holder for? The black, plastic ring found on your Signature's portafilter holder is the [adaptor ring](https://flairespresso.com/product/adapter-ring-pro-classic/?__hstc=233546881.4b0367aca4ddae800dfef9f5eafbbfdf.1649620184124.1660961988399.1661214670469.30&__hssc=233546881.7.1661214670469&__hsfp=2541766894). Keep it in place when using the Standard brew head, or remove it if upgrading to/using the larger [PRO2 Brew Head](https://flairespresso.com/product/full-pro-2-brewing-head/?__hstc=233546881.4b0367aca4ddae800dfef9f5eafbbfdf.1649620184124.1660961988399.1661214670469.30&__hssc=233546881.7.1661214670469&__hsfp=2541766894).  flairespresso.com Help Center - [Go to flairespresso.com](https://flairespresso.com) - [Contact us](https://support.flairespresso.com/knowledge/kb-tickets/new)