Features:Upgraded pocket size 3-wheel auto dolly, 5 speeds adjustable, 4mm/s(default), 7mm/s, 11mm/s, 17mm/s, 24mm/s.The front wheel is 180 rotary, so the dolly can move in straight line / circle route and opposite direction.Use low noise motor, 60DB, ensure a quite shooting environment.Powered by 14430 battery, can work for 1h at max. load, 10hrs for smartphone; USB rechargeable.Comes with an angle adjustable ball head with 1/4 screw and a with 1/4 3/8 convertible connector.An ideal helper for GoPro 5/4/3+/3 etc action camera, smartphone, camera, DV etc video making.Heavy duty aluminum alloy body, can carry up to 4kg/8.8Lbs load.