Review on 🚲 Mini Bicycle Frame-Mounted Air Pump Kit for Presta & Schrader Tires - Portable, Accurate Gauge, 150 PSI High Pressure Inflation - Suitable for Road, Mountain, and BMX Bikes by Jared Coleman

I've seen other reviews that say air volume and pressure hurt usability and that's for sure. Difficult to use on a mountain bike (i.e. low pressure, high volume). You will pump a lot, which can loosen the connection to the valve and cause a leak. The exterior is also sleek, making it slippery and difficult to use when it's hot and you're sweating. But it works and the sensor seems to be accurate. All in all, a decent little pump that gets the job done, but I wouldn't count on it as a main pump.