4 pieces sliding window locks stop aluminum alloy door frame security lockEasy 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 took full advantage of many times.Wide usage: It 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.Specifications:Size: 3 x 2.4 x 2.4 cm/ 1.18 x 0.94 x 0.94 inch(LWH)Material: aluminum alloy and stainless steelQuantity: 4 piecesPackage includes:4 x Sliding window locks with keys