I just got a DM5 and I wanted to clean every o-ring. I was told that the gun had a small leak from the on/off area. So I dissembled the gun and took the on/off part out. The middle o-ring had a slight tear on it so I decided to replace it with an o-ring form my dm o-ring kit. The problem is I never bothered to pay attention as to what end is "up" for the on/off. When putting the part back in is the middle o-ring facing left or right or does it matter?