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.
Draper SIDE LEVER GREASE GUN 500CC 47807 47807 Grease Gun, 500cc
Sealey Side Lever Grease Gun 3-Way Fill Standard Grease Gun Equipment/Tool AK445
Lumatic VSLGH Side Lever Grease Gun & Volcatec Lithium EP2 Grease Cartridge
Lever Grease Gun Heavy Duty Spring Plunger 400cc Single lever action 400g
Lumatic Lube-Shuttle® Side Lever Grease Gun
