Taran Tactical Innovations g17 (TTI) Build List... The lower ... Guarder frame, guarder chassis, guarder spring kit, guarder mag release (extended), guarder steel slide lock lever, guarder pins, UAC hammer housing, brand new AIP hammer set with ball bearing rotor (makes for extremely smooth crisp cycle) , UAC trigger bar. and Guns Modify SAI trigger and Slide release The upper... TTI slide and outer barrel , Guarder light weight bbu, Gurader rod and spring, Gurader nozzle , Gurader hop up , PDI inner barrel , UAC bucking. This build is solid as hell and drives nails !!!