Fosmon 51006HOM Wireless Doorbell with Portable Flashing Vibrating Receiver for Noisy Environment, Warehouse, Factory, Offices, Senior - 1 Remote, 1 Plugin, 1 Portable Vibrating Receiver w/Belt Clip Maximum of 820 ft/ 250 m operating range Modern and contemporary design gives flexibility to install anywhere in your home 52 unique chime tunes and 4 volume levels Built-in LED indicators create visual alert Easy to install with the accessories provided Maximum 820ft / 250 m operating range in open area 52 unique ringtones 4 volume levels LED indicators Wall receiver has 4 notification modes: Flashing, ringtone, Flashing + ringtone, Off Portable receiver comes with a built-in LED and vibration indicators Transmitter battery: A23 12V Alkaline Battery; Portable Receiver battery: two (2) AAA 1.5V Alkaline Batteries Transmitter power consumption: &lt;10mW Volume range: 65 to 110dB Operating Frequency: 315/433 MHz  2MHz Operating Temperature: 5F to 140F or -15C to 60C Dimension: Receiver: 3.17 x 3.19 x 1.12in / 80.5 x 81 x 28.5mm; Transmitter: 2.80 x 1.61 x 0.71in / 71 x 41 x 18mm; Portable Receiver: 3.58 x 2.24 x 1.06in / 91 x 57 x 27mm Weight: Receiver: 3.03oz or 86g; Transmitter: 0.85oz or 24g; Portable Receiver: 1.76oz or 50g One (1) wall receiver, one (1) portable receiver, and one (1) transmitter Double sided tape, anchors, screws, and batteries for transmitter Maximum of 820 ft/ 250 m operating range Wall receiver has rechargeable batteries for power outages. Portable receiver included for usage in areas without a power outlet Modern and contemporary design gives flexibility to install anywhere in your home Both receivers have 52 unique ringtones and 4 volume levels Built-in LED indicators create visual alert for elderly or hearing impaired Customize and expand the doorbell selection depending on your needs Easy to install with the accessories provided Compatible with Fosmon WaveLink Series Receivers, Sensors and Doorbells. The following SKUs are compatible with each other: 51004HOM 51005HOM 51006HOM 51007HOM 51008HOM 51009HOM 51018HOM 51032HOMGB 51036HOMUS 51044HOMUS 51046HOMUS