Use skills

Thirdly, there are some failures in use. Many failures in use are caused by its own operation, so we can try our best to avoid them. Once you've got a few grains of sand in the butter, and you're using a pointy mouthpiece, you're guaranteed to get angry enough to throw the gun, and there's absolutely no benefit to the equipment, but it's mostly self-inflicted. Therefore, it is necessary to keep the butter clean, do not use dirty tools to refuel, and put oil containers should be covered in time.