Specifications: Power Supply Method: Polymer lithium battery Battery Powered: DC5V/1A Working Temperature: -20 ° C~55 ° C Transmission Distance: open space of about 1000m/3280ft, partition walls of 20-100m/66-328ft, floors 1-8 Working Frequency: B-gear frequency 462MHz, A-gear frequency 434MHz Working Time: Charge once for about 3 days Charging Time: Approximately 5 hours when fully charged Music Ringtones: 38 ringtones Ring Volume: Level 3 adjustment (standby machine volume adjustment key) Call Sound: Level 3 adjust call size (adjust volume key during call operation) Product Quantity: 2Pcs Product Colors: Black, White (optional) Product Size: 116 * 56 * 18mm/4.6 * 2.2 * 0.7inch Charging Dock Size: 70 * 56 * 29mm/2.8 * 2.2 * 1.1inch Note: 1. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! 2. Please allow 1-2cm measuring deviation due to manual measurement. Package List: 2 * Indoor Intercom 2 * Charging Dock 2 * Charging Cable 1 * Instructions 💎3280ft long distance, suitable for big house or outdoor use 💎Two-way instant call, clear sound quality 💎One button operation, suitable for the elderly and children 💎Portable design, rechargeable battery life, no wiring required 💎Suitable for home, office, warehouse and other scenes