I love this mini inflator head, it's the smallest I've found. It doesn't have a trigger or pump action, just the simplistic twist to tighten and then twist to release mechanism that you'll find on cheap inflators. You'll want to make sure you have to proper cartridge size for your PSI. As with most of these, unless it fails catastrophically pointing to poor build quality, most folks' gripes with CO2 inflators come down to user error (which I have plenty of experience with myself). It does get excessively cold because of the physics of such a small head, but it doesn't freeze your fingers unless you manage to pop it off the valve stem. As always -- sacrifice a few canisters at home when learning a new system. You'll want to know you can air up consistently instead of being stranded.

I got this thing a while ago and I don't believe it came with any instructions but how hard could it be right? Well I wasted like 3 CO2s before I figured out your supposed to tighten the head a bunch and then loosen it to inflate your tire. It's a sweet design, super compact and simple but some directions would have been nice.

I felt compelled to write this because of all the bad reviews. The design is clever, but by no means intuitive, and like other people note your fingers will get cold. That said I was able to reseat my tubeless bead first try. I'll keep it in my bike bag for emergencies but I do prefer the spring head design of other inflators. I wouldn't recommend it over spring head designs, but it gets the job done. It seems like specialized was trying to get around a patent or two with this one.

I had to use this and everything went to play until the o-ring exploded from the device. I have been unsuccessful in finding a replacement or a way to determine its dimensions so that I could replace it.

This came with my SWAT box; love how tiny it is. Unfortunately, it failed in the same way as for other reviewers. Good thing I carry a backup pump...

Screwed in cartridge, seated it on stem. Then backed it out and all that happened is cartridge empty, tire didn't blow up. Junk!