Nflightcam 110mm Vacuum Suction Cup This vacuum pump suction cup is the professionals' go-to mount when they need a strong hold. It is designed to hold on any smooth non-porous surface, but for best result, mount the suction cup on glass, metal, or non-porous plastic surfaces. The side pump creates a vacuum for the suction cup base that is second to none. The red warning line on the pump indicates if a leak has compromised the holding power.