Upgraded Double Glazed Locks - Double glazed locks can be applied to heavy doors or windows for added security. And it will be more solid, solid and sturdy, exquisite , aluminum alloy frame and stainless steel screws that can be reused many times Quantity and size - double sliding window locks with 4 keys; volume approx. 6 x 2.5 x 2.2 cm (LWH), track thickness not more than 1.6 cm / 0.63 inch (not applicable to the middle track window, please check your window track Easy to install - no need to install additional tools, it has a hex key in each window lock, held by a key control on the track. Designed for horizontal / vertical windows and sliding glass doors; Not for plastic window frames Wide use - can be easily applied to most environments; By keeping the windows partially open and closed, theft and thieves can prevent children from falling and protect the safety of their families while improving air circulation Size: 4 Pcs Double Locks 4 Pieces Adjustable Double Sliding Window Locks Stop Aluminum Alloy Door Frame Security Lock with Key Easy to Install: There is no need to install additional tools, it has a hexagonal key in each window lock, held on the track by key control. Durable Material: It is strong, solid and sturdy, with exquisite, aluminum alloy frame and stainless steel screws that can be fully exploited. Wide Usage: It can be easily applied to most environments. By keeping windows partially open and burglar-proof, anti-theft and thieves can prevent children from falling and protect the safety of their families while improving air circulation. Features: Size: 6 x 2.2 x 2.5cm Material: Aluminum alloy and stainless steel Quantity: 4pcs Package includes: 4 x Double Sliding Window Locks with 4 Keys Note: Multiple locks can be applied to heavy doors to enhance security. Quantity: 4pcs Product color: silver, key yellow Product size: 6 x 2.4 x 2.2cm. Note: Manual measurement, please allow 1-3mm error.