I like it! Actually I was cruising the Internet the other night for one that fits the Colorado too and it looks like the Stant 10591d or 10501d might work but I'm not in an experimenting mood.
Yes. Bio Environmental Modifiers. I ordered one a couple of months ago for my 2016 Colorado Duramax. They are located Kansas. They make them out of billet aluminum with a special key to open. It will set you back $100 plus tax, but the peace of mind is worth it. This is the only place that sells a locking cap, trust me. Save yourself hours of looking. They took down their website since they started manufacturing directly to distributors, but the will sell direct to consumer if you call.I would like a locking diesel fuel cap, can't find any! anybody have any suggestions?