Retevis RT21 Walkie Talkies Rechargeable 16 Channels FRS License-Free 2 Way Radios( 4 Pack) These License-free walkie talkies features 16 FRS channels keep your communication free from interference Superior cell make it crystal although in the noisy environment and keep long range Enhanced accessories will empower your business with a smoothly and effective way Two knob easy to operate for every group member and same channel to working directly Simple and Convenient return process;1 year radio warranty and 2 month warranty for accessories;30 day return with no questions asked