Security auxiliary lock for sash windows, providing peace of mind with its high-strength locking function. - Model Name: Sash Lock SLIM - Quantity: 4 pieces (3 unused as one was used. See photo 3. The double-sided tape seal has been removed.) - Application: Security auxiliary lock - Installation: Easy installation - Features: High-strength locking function - Size: Approximately 5.8 x 2.5 x 0.3 cm - Materials: Stainless steel, adhesive tape I purchased these for security, but I gave up on using them because the sash frame is resin and the double-sided tape didn't adhere well. I used one, but it seems possible to install them if you use commercially available double-sided tape. Shipping may use recycled materials. Thank you for your understanding.