The Doro MemoryPlus 335 Locator is a lost item location system designed for use by individuals who are blind or have low vision or with cognitive or memory disabilities. When an item is connected to a wireless sensor and misplaced, pressing the corresponding sensor button on the remote transmitter causes the sensor emit a repeating beep to aid in locating the item. The system has a range of 90 feet and includes the remote, two key ring sensors, a key ring clip-on sensor, and a credit-card-sized sensor (can be placed in items such as wallets). The remote unit also sounds a reminder if not returned to its cradle. POWER: The remote uses 2 triple-A batteries, the key ring sensors use 2 CR2032 batteries, and the credit card sensor uses 1 CR2423 battery (all included). DIMENSIONS: The remote transmitter is 5.7 x 1.8 x 0.9 inches. The key ring receivers are 2.0 x 1.3 x 0.5 inches. The credit card receiver is 2.7 x 2.0 x 0.2 inches.