Ansoko 20 Pack Walkie talkies Long Range with Earpiece Rechargeable 2 Way Radio UHF 400-470MHz 16-Channel for Outdoor Warehouse Factory Security Com Travel etc.(Pack of 20)

You might want to know how far it actually can transmit? Our testing staffs have done the test in built-up areas where tall buildings surrounding and they reached 0.6 miles or so,We also done a test in a coastal bay, nothing but the sea between two...