When you have a barn full of equipment and it's time to lubricate them, a hand pump grease gun is handy. After several hundred strokes however, having the ability to power those strokes through a battery or air powered gun makes a lot of sense. We have seen and admired battery operated guns, but they are limited to the size of the standard 14OZ cartridge. If working on big machines, you could cycle through several in a day. We also are not fans of the hand pump guns due to issues with lack of pressure. This Vevor 5 gallon grease pump and pot should solve the high volume demands of a maintenance shop. With an air pressure powered supply of grease and a generous 13 foot long hose, the wheeled pot is only limited in reach by your air supply hose. When we received this pump, it included an extra air hose fitting (male), some miscellaneous \"fittings\" and a set of wheels. The fittings are a paper pad, a slider and a sealing ring. These parts are not clearly described, though we trust they replace wearable parts within. The wheels need to be assembled onto the pot. Be careful when doing so as the bottom steel canister parts are stamped metal and can be sharp enough to cut. The lid is held on with 2 spring clamps. Releasing them allows removal of the entire upper assembly and reveals the compartment where the grease is loaded. The lid is hard to remove due to no internal residual grease, so the rubber rim of the plunger grips the inner walls quite tight. Twisting and angling the upper assembly allows air into the lower chamber and eases removal. The Amazon page shows an image of a bucket of grease residing inside, but we doubt the accuracy of this. The pot will accept the bottom of a 5 gallon bucket, but about 1/2 way in, the flare or the bucket stops it from entering any deeper. We also wonder if the rubber edged plunger would work within the confines of a plastic bucket. This greaser is probably best used with the grease scooped into the steel bucket. The