Handheld shape design, comfortable hand feel . 2 buttons for simple operations. Standalone operation, no need to connect with computer or PC, easy to use. Built-in individual LED lights and buzzer indicator. Reading distance is 0 - 6cm. Can only copy 125KHz RFID card. Compatible with T5577, 5200, EM4305, EN4305. Read: 125KHz ID (EM4100, TK4100, etc.) cards or keys. Write: 5200, EM4305, T5577, 8310, 8268, etc. cards or keys. Built-in individual LED lights, buzzer indicator, and transceiver antenna. Power supply: 3V (2 x AAA battery), not included. Rated for 20,000 read/write cycles. Tested before shipment. If the device does not read a card, the card may be of an unsupported type. If the device does not write to a card, the card may be of an unsupported or non-writable type. These conditions are not due to device defects. Product appearance, color, and printed text may vary slightly between batches, but this does not affect functionality. Type: 1 Keyfob Color: Blue Material: Plastic Package contents: 1 x RFID Card Reader Kit Note: Light reflection and differences in display screens may cause slight variations in color representation. Measurement error allowance is +/- 1-3 cm.