After buying the pump I had the same problem as the buyer who submitted such bad reviews: Although the pump will both fit on DV and AV valves (My bike has two valve variants), has not fit the pump head on my valves he always slipped. I then complained to the seller, who declared immediately friendly and helpful, as the pump works (there is no description in the supply). So before you complain about the pump, try only the following:
The pump head has a small lever. I thought you just put the head on to the valve and then press the lever down to grip him. So around it is exactly wrong (although that would probably most once try so). Man must release the lever down, put his head on the valve and only then lift the lever. So it worked out.
Value is in order, the pump acts not too high and the hose is relatively short, but for the price I am very satisfied.
