This is a replacement cylinder for Miwa Lock. It is often used for entrance doors of apartments, houses, and offices. Since it is a 2-key-same type, you can lock and unlock the upper and lower locks with one key. Four keys are included. It was used on the entrance door of an apartment building, but it was not exposed to rain. Brand: MIWA LOCK Accessories: 4 keys All keys are genuine products. Condition: Used Color: Gold It doesn't mean you can't use it unless it's a two-door-two-lock system. I think the keys and the lock body have the same specifications, so you can install it on another door without sticking to the two-lock system. Of course, you can use only one and keep the rest as spare parts. I have added a little supplement. * Due to the nature of keys, we will only conduct transactions with anonymous shipping, and we cannot accept returns or refunds. Please consider carefully before purchasing. The product will be shipped in the box of another product that was replaced, as "PC parts" via Yu-Packet Plus. * Because it is a used item, there are some signs of use, dirt, and scratches. Please refrain from purchasing if you are nervous, and only purchase if you understand. We will also accept bulk purchases. Thank you for viewing.