Features 1、Easy Control: The wireless controller enables convenient and flexible remote control on the crane, very useful. 2、Wide Utility: Suitable for bridge crane, top cranes, chain cranes, monorails , concrete pump trucks and so on. 3、Sturdy Shell: Sturdy ABS shell is very comfortable to hold, which is also waterproof, insulating and durable. 4、Working Tips: Needs to use with contactor. Cannot connect directly to the power source since it will damage the motherboard. 5、2pcs Switch: Including 2pcs control switch with clear panel, making the operation much simpler. Specification Item Type: Crane Remote Control Product Material: ABS Product Model: YU-4S Temperature Range: -5~85℃ Radio Frequency Point: 800MHz Protection Grade: IP68 Control Distance: Approx. 100meter / 328.08ft (in open environment) Adapter Battery: 2 x 1.5V AA battery (delivered without battery). Package List 2 x Crane Remote Control 1 x Transmitter 2 x Protective Cover 2 x Fuse 1 x User Manual