VARILITE Drop Base is made from durable and lightweight 3/8-inch (1 cm) PVC. Our L-J brackets are hardened steel for superior strength and durability. The hardware allows 4 inches (10 cm) of height adjustment and 15 degrees of angle adjustment-great for changing the seat-to-floor height or seat-to-back angle. The VARILITE Drop Base is essential for wheelchair users who need to sit lower for self-propelling or transferring.