It is a Milwaukee M12 gun with a LockNLube coupler. For the last twenty five years I have used a pneumatic gun. I grease outside in the yard where our work trucks are parked and I have to move the trucks over to where the air hose is. I don`t have to do that with this cordless gun. The gun came with a 3 foot hose and I extended it by another 2 feet for a total length of five feet. The extra length is useful when greasing driveshaft u-joints while lying under the truck because I can leave the gun in a cardboard box on the ground and just squeeze the trigger without having to hold the gun up in the air. The LockNLube coupler works well and frees up one hand for other duties like holding a flashlight or feeling a rubber boot for grease flowing in. I have used this setup for three weeks now and am pretty happy with how it works. A bit expensive at $200 Cdn for the gun and $30 + $10 shipping for the LockNLube coupler but it saves me some hassle and I grease frequently enough to justify the expense.