Polycarbonate with thick cushioned pads to prevent marring. Extra-wide base, high walls and strong Acme-threaded clamp screw hold panels securely. Mounting holes allow for attachment to work surface for creating assembly jigs. Polycarbonate with thick cushioned pads to prevent marring. Extra-wide base, high walls and strong Acme-threaded clamp screw hold panels securely. Mounting holes allow for attachment to work surface for creating assembly jigs.