Thank you for viewing. Sanwa-made USB-connected numeric keypad with Num Lock function. - Brand: Sanwa - Connection Type: USB - Key Arrangement: Numeric Keypad - Features: Equipped with Num Lock function Due to poor contact, it sometimes works and sometimes doesn't. It's a retractable cord type and doesn't require batteries. Other than the poor contact issue, there are no other problems with the buttons, etc. I'm not sure if there's a demand, but please consider purchasing only if you understand the above!