It comes complete with all the seals, unloader, check valves, chemical injector, ez start valve, inlet and outlet tubes and thermal valve. Verify that the pistons are moving in the crankcase. If they are just use this head. It fits both the standard (labeled as EZ) and the EZ-SX version of the pump. If you have the RMW2.5G28 or SRMW2.4G28 this head will NOT work.Fits RMW2.2G24 and SRMW2.2G26 Pumps. Pump srmw 2.2g26 318644. Troy bilt 020292-2 rmw 2.2g20 pump. Troy Bilt 020416 3000psi 2.7 gpm. Troy Bilt Briggs Stratton 020568 2800 psi pump srmw 2 2626318644. Troy bilt model 020414 s/n 1018382982 Pump 311966gs. Troy-Bilt 020337, revisions 1 or 2. Please check out your address carefully when processing order. We care about our valued customers, and will always try to help you. Please give us the opportunity to resolve any problem. We understand the concerns and frustrations you might have, and we try our best to resolve the problem.