This is simply the easiest way to inflate tires. Overall assembly is good. Bring your own teflon tape. Mounting on valve stems is good. When you pull the trigger, the reading will show (almost) pressure in your air line as the tire fills up quickly. When released, it takes a second for the tire pressure to stabilize. Pressing the reset button (the silver button below the sensor) does the opposite. shows about 12psi as the air is expelled quickly. Additional accessories (valve caps, right angle) are not worth the extra $5. Stick to the basic package.