Features: 1.Made of ABS plastic, durable and waterproof, stylish modern design in classic white. 2.52 different style doorbell sound available, all loud and clear, choose your favorite doorbell ring. 3.High frequency emission technique, operating range of over 400 meter, stronger penetration than average product. 4.It's difficult for patients and the elderly to scream when they need help, using this doorbell to alarm family members with just one click. 5.The volume of doorbell can be adjusted to 4 position, find a perfect sound volume that loud enough to alarm, yet prevent from frightening kids or the elderly. Specifications: Item Type: Wireless Doorbell Material: ABS Color: White Working Pressure Standby Current Working Current Working Frequency Size (cm/inch) Receiver 110-260V 7mA 60mA 433MHZ 7.2*7.2*4/2.8*2.8*1.6 Ejector 12V 1pA 12mA 433MHZ 8.3*3.4*1.9/3.3*1.3*0.7 (350MAH Battery Include in The Ejector) Package List: 1* Receiver 1* Ejector 1* English Manual 1* Sticker 2* Screw 2* Plastic Expansion Bolt 1、Made of ABS plastic, durable and waterproof, stylish modern design in classic white. 2、52 different style doorbell sound available, all loud and clear, choose your favorite doorbell ring. 3、High frequency emission technique, operating range of over 400 meter, stronger penetration than average product. 4、It's difficult for patients and the elderly to scream when they need help, using this doorbell to alarm family members with just one click. 5、The volume of doorbell can be adjusted to 4 position, find a perfect sound volume that loud enough to alarm, yet prevent from frightening kids or the elderly.