Includes two rubber backflush disks in 50MM and 57MM sizes to fit different portafilter baskets, enabling regular backflushing cycles that remove coffee oil residues and buildup from internal brewing components to help maintain espresso machine performance. Tight seal for effective cleaning: Rubber construction creates a secure seal in the portafilter basket, allowing cleaning solution to circulate through internal pathways while preventing water and cleaning agent leakage during maintenance. Broad compatibility: Engineered to fit most standard espresso machine portafilters with 50MM and 57MM basket sizes, suitable for both commercial and home equipment to support comprehensive brewingsystem maintenance routines. Durable rubber material: Black rubber withstands repeated exposure to hot water and cleaning solutions, maintaining sealing properties across multiple backflushing cycles and safe for contact with brewing equipment. Use scenarios Cafe environment: Use both disks during regular backflush cycles between shifts to purge oil residues and keep group heads clean. Home espresso setup: Include weekly maintenance with the appropriate disk to preserve espresso quality and machine longevity. Equipment upgrade: Add to your cleaning routine to ensure cleaning solution circulates effectively and leaks are avoided during backflushing.