Select a Product Part NumberSize WS-400-0024" BISO, 4" SISO WS-250-0022", 2 1/2" BISO, 1¼", 1½", 2" SISO WS-600-0026" BISO WS-300-0023" BISO, 2½", 3" SISO WS-150-0021", 1 1/2" BISO, 1" SISO