... warranty. Defective products can be changed during the warranty.2) Defective products must be returned within 30days from ... defective, damaged, or misrepresented item within 7days.1. 2.4G corresponding with ISM(industrial, medical, industry)frequency automatic ... , effectively avoid the interference between the wireless devices 2. 2.4G wirelesstransmission can reach 10 meters barrier-free distance ...