Features: *100% brand new and high quality *Sturdy and durable, finish machined, aluminum frame and can be reused many times with stainless steel bolts *Use a hex wrench to adjust the stainless steel screws to suit the thickness of the frame *Suitable for track height greater than 15.0 mm / 0.59 inch and track thickness not greater than 16 mm / 0.63 inch *Wide Application: Can be easily used in most environments; by partially opening and closing the casement, the anti-theft device can prevent children from falling and improve air circulation to protect the safety of family Specifications: *Material: Aluminum Alloy + Stainless Steel *Key Length: 47mm / 1.85 inch (Approx) *casement Lock Size: 30mm * 24mm * 24mm / 1.18in * 0.94in * 0.94in (Approx) *Weight: 148g / Set (Approx) *Color: Silver (As Pictures Show) Package Contents: 4 * casement Lock 4 * Wrench Note: The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. Size: volume approx. 3.0cmx2.4cmx2.4cm / 1.18x0.94x0.94inch, apply to track heights more than 1.5 cm/ 0.6 inch,track thickness no greater than 1.6 cm/ 0.63 inch (not applicable to the middle track of the window, please check your window track before buying) Easy to install: there is no need to install extra tools, it equips a hex key in each window locks, holding on the track by key control Durable material: it is strong, solid and sturdy, exquisite workmanship, aluminum alloy frame and stainless steel screws that can be reused many times Wide usage: can be easily applied to most environments; By keeping the windows partially open and closed, the burglar-proof and thieves can prevent children from falling and protect the safety of their families while improving air circulation Quantity: 4 pieces sliding window locks with keys; Note: multiple locks can be apply to heavy doors or windows to increase safety