【IP44 Waterproofing】: The transmitter is splash-proof (equivalent to IP44 waterproof standard), offering excellent waterproof and dustproof performance, allowing use outdoors or in the bathroom without worry, even on rainy days. However, avoid submerging it in water or using it in areas where it will be directly exposed to rain. 【Stable Transmission】: This doorbell chime can transmit wirelessly up to 300 meters (manufacturer's specification) in an unobstructed area. The high-sensitivity receiver can stably receive signals through walls, wooden doors, steel doors, etc., and can be used in two-story buildings. Installation is easy without any construction. 【Volume Adjustment & 36 Melodies】: The loud doorbell sound can be adjusted in 4 levels, with a volume range of 0dB to 100dB. 36 melodies are selectable, satisfying a wide variety of environments and needs. Recommended for those with hearing impairments due to the loud volume. 【Easy Installation】: This entrance chime requires no wiring. The doorbell receiver is battery-powered, and you simply fix the transmitter to the door frame (adhesive tape can be used) and press the button to play the chime. Installation is easy without any construction, making it very convenient. Children and the elderly can also use it. 【Wide Range of Applications】: Can be used for home security, restaurants, offices, hotels, and nursing care facilities. It can be used in various environments. In addition, it is useful for calling at the entrance, reception, dining, and for visitors, as well as for those who need assistance in izakayas (Japanese pubs), and it is applicable to various scene needs.