Dual Clam Shell with Large - Powder coat - Clam Shell features the following hole patterns: AMPS, NEC and 75mm VESA, Gamber-Johnson 2 x 4.09; Tilt Capabilities: 90 forward allows for tablets to be easily mounted 26 aft movement with a positive stop at 26 Riveted design allows for smoother tilt movement; To tilt the Clam Shell, simply loosen the adjustable lever, tilt to desired position and then re-tighten the lever; A secondary bolt is included to lock the clam shell into a permanent position; Heavy gauge steel construction for long-term durability in a rugged environment; Black powdercoat finish for maximum corrosion resistance