HP130's are seemingly inexhaustible after diving smaller tanks. I have 100's, 120's and 130's.You're absolutely correct. I didn't notice it the first couple of times I looked at the tanks. However, they are stamped XS Scuba. I didn't mention it in my previous posts because I didn't think anyone was that familiar with them. I'm very happy I stumbled into purchasing them. I've been very happy with my HP100s even though they aren't Worthingtons. I can't wait to try out the 130s this weekend.