This bed frame is a strong and versatile option for supporting your mattress. The black frame is made of heavy-duty steel rails and is easily extendable to fit twin, full, queen, king, or California king sizes. A center support rail provides extra support. Six legs hold up this frame, two with glides and four with caster wheels for smooth movement. Two of the wheels lock to immobilize the frame in place. Headboard attachment is made easy with the included two headboard brackets (headboard not included).