Features: BT connection, up to 10m transmission distance, stable signal, low latency. 28 independent keys, compact layout, easy to carry and use. Small size, slim and lightweight, easy to carry and use. Ergonomic design, the keycap fits your finger, relieve fatigue and improve work efficiency, comfortable typing experience. Suitable for cashier desk, bank, financial accounting, business office, shopping mall, etc. Built-in 140mAh rechargeable lithium battery, long endurance time, no need to change the battery. Specification: Type: Numeric keyboard Material: Aluminum alloy Connection method: BT Transmission distance: 10m(barrier-free) Key number: 28 Battery capacity: 140mAh Item size: 12.1 * 10 * 1.25cm /4.76 * 3.94 * 0.49in Packing list: 1 * Keyboard 1 * Data cable 1 * User manual