Features: Silver aluminum accessory mount with 1/4-20 and 3/8-16 thread tapped holes for attaching equipment. 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. Not for use on thin, fragile materials. Red-line indicator warns user of any vacuum loss. Check valve allows repumping without loss of remaining vacuum. Easily replaceable handle/release valve and plunger. Supplied with vacuum pad protector. Specifications: Vacuum Pad: Concave, 10" [254 mm] diameter (model G0750) Minimum Radius for Curved Mounting Surface: 13" [330 mm] Load Capacity: 175 lbs [79 kg] per vacuum cup