Soooo, I just received my second Aquatek minI w/ regulator in a span of 2 months. The first one was completely broken, no gas would pass through it and the output guage always read 50 psi. Total trash. I tried to get a replacement but aquatek never responded. Against my better judgement I bought a second one. They're like $100 and can be used with a 20 oz paintball tank which sounds way better than a DIY I have to feed or a $700 setup with a ugly tank, so yeah. Anyway, I just got the second one and the **** o-ring is missing...... I tested it with a rubber o-ring but that's a horrible idea for long term and shut it down. Anyone know what type of o-ring I should be looking for? The material would be the most important part, I have no idea what to ask for when at the hardware store. Aquatek is no help so far and any help would be appreciated.