Camera, keys, TV remote, phone--if you can lose it (up to 400' away in a clear line of sight), Loc8tor's Loc8tor Lite can help you find it fast. Put one of the included homing tags (weight: 0.17 oz/5 g) on an item that seems to wander off on its own, pick up the included handset (the size of a credit card), and you'll be guided by audible and visual cues to within 1" (2.5 cm) of what you're looking for. The handheld unit uses 1x CR2032 batteries and each tag operates using a single LR54 battery. Batteries are supplied with all packs. No needle will ever be safe in a haystack again.