The Uniphos One Hand Operation Adapter can maintain a vacuum of 50ml or 100ml in the pump body for up to 120 minutes, when used with the model Uniphos ASP-40 Air Sampling Pump. This allows the user to assemble the pump and appropriate tube to take the sample by using one hand, necessary in dangerous situations. In the Adapter, particularly in the body, there is a small rod which can be moved easily in or out with one finger. It acts as a check valve. If the end with the red dot is pushed, the pump works normally and sampling is carried out in the usual manner. When the end of the rod, which is polished metal (unpainted), is pushed in, a vacuum is created and the effect is similar to doing a leak test.