Geberit HDPE Adaptor Socket (also known as a PE adaptor sleeve), a fitting used to connect different sizes of drainage pipes in sanitary installations. 
Key Details and Compatibility
Product Type: An adaptor socket for drainage pipes.
Material: Made from high-density polyethylene (HDPE) plastic, which is resistant to approximately 95% of all standard alkalis, acids, and chemicals. It is also UV-resistant.
Dimensions: It is designed to connect a 90mm PE connector to a 110mm socket (DN 90/100).
Function: The adaptor creates a secure, leak-proof connection with a lip seal made of EPDM rubber. It is suitable for use in various drainage applications, including building drainage and industrial facilities.
Compatibility: This part is suitable for use with Geberit Duofix systems and fits specific concealed cisterns, including:
Geberit Duofix for close coupled cisterns.
Geberit Duofix low height (post 2010 models).
Geberit Duofix with Omega 12 cistern (post 2014 models).
Geberit Duofix with Sigma 8 cistern (post 2010 models).
Geberit Kappa 15 - UP200 with Duofix frame (2006-2016 models).