12 Pack Plastic Spring Clamps, 3.5inch Small Heavy Duty Clips for Crafts, Backdrop Stand, Woodworking, Photography Studios (Black) - Amazon.com
Boxer Tools Silver Aluminum C-Clamp Canopy Clamp for Pickup Trucks - Heavy Duty Construction - Includes 3/8-in x 3-in Screw - Standard Size in the Clamps department at Lowes.com