W Series Replacement SeatsVolcanic Black Replacement Seat for the W Series stroller wagons. The seat comes with seat harness(es), crotch and shoulder pads, the white board and frame inserts, a buckle to attach the seat to the frame, and the seat frame clips. The older, Version 1 of the W2 seats has smaller, round side frame clips to fit on the round wagon frame pieces of the older, Version 1 wagon frame. The newer, Version 2 of the W2 seats has larger, oval side frame clips to