Improved 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 for many timesEasy to install - it is not necessary to install additional tools, it has a hex key in each window lock, held by a keyed control on the track. Designed for horizontal/vertical windows and sliding glass doors; Not for plastic window framesWide use - can be easily applied to most environments; By keeping the windows partially open and closed, the burglars and thieves can prevent children from falling and protect the safety of their families while improving air circulationQuantity delivered: 4 piecesProduct color: yellowSpecifications: as shown in the picture (measure the window size before purchasing).