This is a set of 4 "Akazu no Mado" window auxiliary locks to prevent intrusion through windows. Easy to install without tools, it's useful for home security. It securely locks the window to prevent it from opening, guarding against external intrusion. It can be used for both the upper and lower frames, and the installation dimensions are 28-42mm. [Product Name] Window Auxiliary Lock Akazu no Mado [Quantity] 4 pieces [Colors] Black, Silver [Installation Dimensions] 28-42mm [Features] No tools required, for both upper and lower frames Although unused, please consider this item with the understanding that it has been stored at home. Thank you.