Fits the AM-10, 1410, AM-12S and can be used on the AM-12 or 1412 (although it is too small a seat for most riders of those trykes). The Snappy Seat System provides added support for the smallest riders. The system consists of a 10 inches wide by 8 inches deep bench seat, a contoured padded back and a safety lap t-strap. The back can be positioned forward/back along the seat and can be angled in several recumbent positions. An H-Harness can be added to provide more stability.