Two types: Massage back cushion and Massage seat cushion 1) Velvet with foam material, ergonomically designed back cushion that gives you the right support where you need it, help to maintain a proper posture and reducing stress on your back muscle. 2) Can relive lumbar discomfort and backaches. 3) Can relieve and relax fatigued back and lumbar muscles. 4) 2-vibration massage electrical machinery are put inside, dispel the fatigue effectively, promoting the blood circulation. 5) Convenient to use with reliable secure DC 12V adapter (CE and UL approved).