Had to send the first unit back because the switch to send power to the cables for jumpstarting had a flaw. It wouldn't stay in position on it's own. Someone had to force and hold it over in order to maintain a connection. Also, the cable clamps require delicate handling. Positive cable snapped in my hand when going to clamp on to post.
The unit feels sturdy otherwise and the overall features are nice so I took a chance and sent it back for another one. It works like it's suppose to. Just have to be aware that this is not a "mechanic grade" unit. It should be fine for most of us casual users. Adding comment on compressor...it takes quite a while to get up to psi. Maybe 2 minutes to get from 38psi to 50psi. Really seems to be working hard during this time./ july 2011 been using this unit for a year now and compressor does not work anymore. Never really had enough power to do a car tire,just good for bike and sport balls. The jump capabilities is what i bought it for and works well except if the battery is completely dead. Might try a more professional unit.