materials and sturdy construction The leg curl extension machine is built from heavy duty steel to provide a stable, durable platform. It delivers a load capacity up to 600 pounds, making it suitable for demanding leg training. Fit and compatibility This leg extension attachment mounts to a squat or power rack and fits racks with hole sizes of 1.6 cm, 1.8 cm, or 2.6 cm (0.6, 0.7, 1 inch) and is compatible with barbell plates of 2.5 cm (1 inch) or 5 cm (1.97 inch) diameter. Please ensure your rack holes are compatible before . Eight gear adjustable The seated leg extension and curl machine offers eight adjustable positions to accommodate different body sizes and training requirements during muscle work. It is described as ideal for strengthening triceps, biceps, chest, shoulders and back muscles. Detachable and compact design This leg curl and extension rack attachment updates the traditional bench design with a detachable, adjustable, easy to store unit. It has a small size and lightweight construction. Includes mounting screws and bolts for easy installation. Use scenarios Home gym setup with a squat or power rack: perform leg extensions and leg curls without occupying extra bench space. Small or space constrained spaces: detach and store when not in use, keeping the workout area tidy. Integrated training routines: use in circuit or split routines to complement upper body work performed on the same rack.