The Needlework System 4 Frame Clamp is designed to hold wood stretcher bars and hoops and weighs just under 410 grams. Once attached to the floor stand, it rotates 360 degrees left or right so that you can easily flip to the back of your work - without loosening or tightening any knobs or wingnuts! The frame clamp jaw opens 1 1/2" wide and is made of safe plastic. It can be attached to the Needlework System 4 Floor stand, the table/lap stand and the table clamp. Each component is sold separately.