I give this product 2 stars because the tip needs to be screwed to the tire nipple. So when you attach and detach the tip you lose air and have to attach and inflate it again. Screwing and unscrewing the handpiece and air loss takes too long. I expected the tip to be easier to attach to the tire nipple. Although it took longer than I expected, I was able to inflate all 4 tires. I am sending this item back to the store today.