A 400g air operated, continuous flow grease gun for fast greasing in applications where low overall grease volume is required.

This is a continuous flow grease gun which means that while there is limited back pressure, the trigger button can be held down and it will continuously deliver grease.
As the pressure rises, the continuous flow will slow down, and from that point grease can be delivered at high pressure by pulsing the trigger button which will cause the gun to deliver a shot each time the trigger button is pulsed (like a single shot gun).