Product information : features: - bluetooth two-way intercom keeps you easily connected to your riding companion for conversation - noise suppression technology can provide best sound for both incoming and outgoing sound - up to pair 6 riders communication(but only 2 riders intercom at the same time) - compatible with all phones with bluetooth features - up to 8 hours talk time, 300 hours standby time specifications: - working voltage: 3.3v-4.2v - bluetooth: v3.0 +EDR - battery capacity: 530 mAh - intercom wireless transmission range: 1200m / 3900 ft - cellphone talk time: approx. 8 hours - standby time: approx. 300 hours - charging time: approx. 2.5 hours - temperature range: -40c - 60 c - gross weight: 220g -battery type: Li-Ion package includes: 1 x bluetooth receiver 1 x stereo earphone with mic 1 x USB charging cable 1 x helmet clip 4 x screw 1 x screw driver 1 x user manual .