Features: Provides a reliable, temporary vacuum mount, without drilling holes. Rubber vacuum pad will not mark or damage most surfaces. Attaches to flat or curved, smooth, nonporous surfaces. Red-line indicator warns user of any vacuum loss. Check valve allows re-pumping without loss of remaining vacuum. Lift tabs on vacuum pad edges permit instant release. Supplied with vacuum pad protector : Cup Diameter: 3 inch Vacuum Pad: Concave Pad Application: Applied to flat or curved glass or objects(car glass) How to use: Clean the rubber pad and object to be sucked Put rubber pad face to object, press suction cup onto object then press blue plunger a few times. When red warning line inside, you can lift or move now. The dust cover has no practical effect and the color is random. Color: black + blue material: plastic Package Contents: 1 x Hand Pump Suction Cup with flexible stand Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.