Frankly, sincerely, honestly, truthfully, etc ... I promise you that when you click "buy" I had a doubt about the value of this thing blowing. Well you will be surprised! That thing is after a efficiency very respectable and has met in less time than it takes me to write the inflation of a rather greedy air mattress in air capacity. More surprisingly, after reading derogatory customer view, I was very surprised that this inflator could also increase the pressure and get back to my cozy bed the expected firmness. I will mock a little bit of me possessors of this tool that had not understood that the mattress having a check valve had to plug this inflator on the right of the inflatable ring. in short, a tool that does not seem much but keeps its promises and forget the suggestions of extra manual inflator he has no need to. And besides, mounted the other way and he aspires empty to the last drop your previously perfectly inflated mattress. Used on the 12 V car he did not drained the battery. Not bad, right?