Unfortunately, the design of the item itself is quite faulty. The piston is having too much clearance around the case. The air could leak easily into the space during the pumping. For this reason, the sucking effect is not there. The rubber adapter could drop off easily and will not seal the connection tightly. Although it's cheap, it does not serve its purpose well if you wishes to free the air 100% from your vacuum bag. No use to me and now just sitting at the corner.