This great footrest is a great item to have when working for long hours, helps to circulate blood flow and reduce fatigue. When in use it can help to keep you in a comfortable posture which enables you to keep refreshed and focused. Can help to reduce tiredness and keep you healthier while working. Features and Benefits Ergonomic Design - Improves your posture by helping your back stay fit and healthy while working.  Textured Design - provides foot massage and prevents your feet from slipping off the angled design.  Study Frame - Heavy-duty high impact polystyrene material.  Anti-skid Legs - Ensures stability and protects the floor from scratches.  3 Heights Adjustable - Elevate feet and legs to 4.25", 5.5" or 6.75". Adjustable Angle 0° to 30° - For maximum comfort tilt easily back and forth for a variety of positions. (can't be locked) Specifications 3 level height adjustable with a free-floating platform that lets you stretch your legs at the correct angle for increased circulatio