Just got this a few hours ago, charged it up, and completely deflated my 2.2" x 700c Continental Race Kings and kept reinflating to 24.5 psi until the battery was dead. I got two full inflations, and on the third inflation, the battery was dead once the tire hit 20.5 psi. That, in my opinion, is excellent value for the money. It weighs less than two CO2 cartridges and a mini-pump, and the form factor takes up less space than the aforementioned items. Some more details about the test parameters. Ambient temperature was 72ºF. This is significant as most batteries suffer from diminished performance in the winter. I'll have to put it in the refrigerator (typically around 38º F to 40ºF, which coincidentally is just above my low tolerance level for 20 miles of gravel riding) and see how it does under those conditions. My rims also measure 25 mm internal. A rim like the Zipp Firecrest XPLR has a 32 mm internal width, which actually increases the volume of air inside the tire (this is why rims with wider internal measurements can run lower tire pressures). Of course, rims with wider internal measurements can run lower tire pressures so... it might balance out. A note about use: It appears as if the air intake is around the USB-C charging port. The port is located in a position where you naturally put a finger right over it. If you do that, it will stall out. It happened twice, but I quickly realized what was happening. I would suggest a way to improve this product would be to move the intake if possible, though this may be limited by the design of the internal pump. Putting the intake on the back of the unit would probably be ideal. I considered giving this four stars, because it doesn't have a feature I want. In reality, this is a feature I'm willing to pay more for SO, for the price they're charging and the value this product delivers, this is absolutely a five-star product, no doubt. Okay, so what do I want? I like the size. In testing this pump I found that my "thumb tire pressure gauge" was calibrated to 20 psi. On several tires, my thumb thought the tire was up to pressure when it hit 20 PSI (so in the field I just have to keep pumping for about 25 seconds longer to hit 24.5, my target pressure for my rear wheel). I would pay more for a device that kept this form factor, but automatically cut off at the desired pressure. The interface to set that pressure would be via BlueTooth and an app. I'm not sure if this is technically feasible. Perhaps there's an indirect way to measure pressure through motor performance as the pressure increases (anecdotally, it sounds like the RPMs may decrease a little as the pressure increases, which might be an indirect proxy for pressure if it was found to be repeatable). So, what does this product mean for me? It means that on gravel rides in more populated areas, I will be leaving the CO2 and the mini pump behind. If I'm solo in a less populated area, I will still leave the CO2 behind, but I will bring a mini hand pump, just in case. Electronics fail, and Murphy is a jerk. Mini-pumps are a pain, but they're a simpler system that is less likely to fail. This is an AWESOME product. I was totally skeptical and thought I'd be sending it back. Well done, RockBros! Read more