Retevis H-777 Walkie Talkie 16CH UHF 2 Way Radio Handheld Two Way Radio(10 Pack) with 2 Pin Speaker Mic (10 Pack) Two knob to operate and have been set well;great for group team to work together Lithium battery lasts longer so that you can using for 5-8 hours after charging about 2-3hours FM radio and built-in LED flashlight provide additional visibility in dark environments They are set at the same frequency before they leave the factory;all of them can work on same channel when out of the box We provide 1 year radio body warranty and 30 days no reason to return including the accessories 10 Retevis H-777 2 way radio 10 Antenna 10 1000 mAh Li-ion battery pack 10 Charging base(Without adapter) 10 Belt clip 10 The sling 10 English User&#039;s manual 10 Speaker mic