Comes complete with factory installed lithium batteries, key chain links, and double-sided adhesive strips Micropower technology guarantees extended battery life – battery typically lasts 18 months and is easy to replace Extremely durable – made from polycarbonate plastic – same material used in bullet-proof windows Ultra reliable – corrosion resistant gold plated circuit board Low battery alert – the KeyRinger beeps and flashes just like your smoke detector when the batteries go low Bright flashing light makes it easy to find in the dark KeyRingers can call each other or be called from your computer, smart phone, or tablet using an application available on the KeyRinger website Multiple KeyRingers can all be called simultaneously or individually - up to 2000 user programmable codes available User has the option to change the volume, response duration, and other attributes Easy to use making it great for everyone of all ages – makes an ideal gift that will be greatly appreciated No other product can beat the KeyRinger for finding misplaced objects. Please note that the KeyRinger is for locating missing objects, it is not intended to located people or used as a paging device. Designed in California and protected by two US patents