Handheld grease gun. In the vast majority of cases, there is no need to flush the engine and flushing can be harmful. What can happen is the flush can loosen harmless deposits in the engine, but then not remove them.
Lever Grease Gun Heavy Duty Spring Plunger 400cc Single lever action 400g
GROZ Sealey Double Lever Grease Gun 1/8 Inch GRODLG
Lumatic 1066/3061173 1066/S Heavy-Duty Side Lever Grease Gun
SGS Heavy Duty Lever Grease Gun Aluminium Head, 500cc Bulk Fill, Up To 10,000psi
Professional Series Lever Grease Gun