Zhiyun Mechanical Follow Focus for Crane 2 allows Real Time Focus for all DSLR and mirroless Cameras by connecting Crane 2 to ZY Play APP, you can use various options and focusing via the phone wirelessly quick installation: mount in 60 seconds Technical Specification Charging Voltage: 5V Built-in Li-ion Battery Capacity: 300mAh Weight: 176g Gear: 0.8 Mod, 24 Teeth Compatible Stabilizer: Crane 2 Charging Current: 1500mA Charging Time: 0.5h Size: 85*46*35.5mm