Slim appearance: the thickness is only 18mm, while the thickness of similar products on the market is more than 22mm 2000 mAh lithium battery: Both the outdoor unit and the indoor unit have 2000 mAh batteries. The outdoor unit works normally, presses 5 times a day, and the call lasts 2 minutes at a time. It can work for about 8 months, and the indoor unit works for about 1 week High-quality material: the button adopts plastic + silicone structure, and the surface has high-gloss UV process, which is super hand-feeling Intelligent and user-friendly design: there are intercom lights and power lights to display, which are clear at a glance Press the ring key and the indoor unit will ring. Press the TALK key to talk directly and use it as an intercom The charging stand for the outdoor unit needs to be removed from the rain cover and placed on the charging stand for charging Power key: 0 gear--off, A gear--A frequency, B gear- -B frequency. If interference occurs during a call, switch the outdoor unit and indoor unit to A or B at the same time Specifications: Power supply: 2000mAh, 3.7V rechargeable lithium battery (outdoor unit and indoor unit) Working temperature: -20℃～55℃ Transmission distance: about 1000 meters in an open space Working frequency: B frequency: 462MHz, A frequency: 434MHz Charging time: about 5 hours to fully charge Music ringtone: optional Ringtone volume: 3 levels to adjust the volume (adjust the volume button when in standby mode) Call sound: 3 levels to adjust the call volume (adjust the volume button when the call is working) Dimensions: outdoor unit/indoor unit: 116*56*18mm Waterproof cover size: 121.5*61.5*31.3mm Charging stand size: 70*56*29mm