Easy to Install - there is no need to install extra , it equips a hex key in each window locks, holding on the track by key control. Designed for horizontal/vertical windows and sliding glass doors; Not for plastic window frames Durable Material - it is strong, solid and sturdy, exquisite workmanship, aluminum alloy frame and stainless steel screws can be reused many Wide Usage - can be easily applied to environments; By keeping the windows partially open and closed, the burglar-proof and thieves can prevent children from falling and the safety of their families while improving circulation Color: silver, yellow Material: Aluminum alloy Small size: 3*2.4*2.4cm size: 6 x 2.4 x 2.5 cm Package Contents: 6 x Sliding window locks with Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.