Because it's not the size that matters...
The H.S.P is the only pump you'll every need for you PEV! This bad boy will fit basically anywhere. It's hella light, it can hit up to 150 PSI and it even has a freakin' light on it! This thing is super ill and you should definitely pick one up!
Keep it in your car, your backpack, your pocket, it don't matter this thing will fit anywhere... Well... Maybe not everywhere.... Please don't try to put this in your butt...