Thomas Valve Assembly Service Kit. Kit includes Valve Assembly Service Kit containing retainer gasket, cylinder sleeve gasket, orings, valve plate, head gasket, reed valves, exhaust passage gasket. Kit is compatible with standard Thomas 175 PSIG UNITS - 2nd STAGE SIDE (This item currently has a tariff surcharge which will be added to your order as a separate line item. Tariff surcharges are subject to change.)