Thomas Valve Assembly Service Kit. Kit includes Valve Assembly Service Kit containing retainer gasket, cylinder sleeve gasket, oring, valve plate, head gasket, reed valves, exhaust passage gasketNOTE: Kit content services one cylinder. Kit is compatible with standard Thomas TA & GH models with coated parts. Kit content services one cylinder. Depending on type of unit being serviced, you may need one or two kits (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.)