Coideal 4.5 inch heavy duty backdrop clamps are made of high quality plastic and metal, containing strong spring, making them more strong and durable than other normal metal clamps. The spring loaded clamp opens up to 2 inches, and the maximum thickness it can hold is 1.5 inches, which can meet your various needs. With these clamps, you can spend more time on taking photos or creating artwork. \nMetal Pins to Secure the Rotatable Pads - The gripping tips of Coideal nylon spring clamps have metal rods through them to keep them on. Moveable teeth help you to clip the backdrop in any direction. Strong spring and the rough surface enable itself to clamp anything onto the stand tightly. \nWide Application - These versatile backdrop clamps are perfect for mounting canvas, paper, muslin, photo backdrop, sheet, wall paper, crossbar, and so on. They are ideal for studio, home, school, office and other occasions. Also a good choice for photographers, artists, designers and so on. Toothed area .