Compact foot rocker footrest promotes comfort in areas with restricted work space. Improves posture and relieves lower back pressure. Rocking motion improves circulation and reduces fatigue. Flip foot support over to adjust height from 2-3/4" to 4". Unique tread design holds foot rocker in place during use. Compact foot rocker is made of high-impact plastic. Packed flat to reduce environmental impact of packaging and shipping, foot rocker footrest assembles easily.