The end part of a fluid distribution system is almost always a gun, i.e. a valve that allows the fluid to pass if a trigger is pressed.
For convenience, over the years it has been transformed into a handy grip with a spout that is easily inserted into the opening of the engine and a drop-collecting end so that not even a drop is wasted.
Different shapes, different materials, and different sizes characterize the use for each application. With or without a digital meter, the fluid dispensing gun is always being used by mechanics and this product makes a significant contribution to the workshop's profitability. That is why you shouldn't take the gun for granted but get a WORKY product!