Thank you for viewing. This is a set of 6 window auxiliary locks, perfect for window security measures. - Model: NEW Akazu no Mado (Unopenable Window) - Installable Dimensions: 28-42mm - Quantity: 5 black, 1 gray Easy installation, no tools required. Locks the window to prevent it from opening! Guards against external intrusion! Installing them on the top and bottom of the window further enhances security. I bought these because I was concerned about home security, but I no longer need them since I moved to an apartment. They provide peace of mind, so please consider them.