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 workmanship, 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 before purchasing) 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 Product Warranty and Customer Service - We do not sell perfect pictures but products; we provide full refund or free reshipment of new products for free if you are not satisfied with our products. 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 workmanship, 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 delivered: 4pcs Product color: silver, key yellow Product size: 6 x 2.4 x 2.2cm. Note: Manual measurement, please allow 1-3mm error.Yeuri