Rowing Machine Seat Cushion fits perfectly over Concept 2 Rower - Rower Seat Cushion Compatible with Hydrow, Concept2 and other Row Machines - Rower Accessories and Seat Pad. FITS PERFECTLY ON CONCEPT 2 ROWING MACHINE: This black seat cushion is designed having the exact specifications of the Concept 2 rowing machine’s seat in mind - so it’s a perfect, snug fit.