Thomas Service Kit. Kit includes 624677 piston cups, 626392 retainers, cylinder sleeves, cylinder orings, head orings, valves, valve keepers, valve restraints, valve screws, head screws, retainer screws, foam filter. Kit is compatible with standard Thomas 2660, 2680 models (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.)