【For Crime Prevention and Safety】Set of 2! Window Stopper Lock, Auxiliary Lock for Sash Black/Khaki (Actual color is closer to gray) ※ If you have no preference, we will randomly send a set of 2 black or 2 khaki. For crime prevention and safety! Also recommended for safety measures in homes with small children. Using two, one on top and one on the bottom, provides a great sense of security. Useful when you want to slightly open a small window for ventilation in bathrooms, kitchens, toilets, etc. Easy to install! Simply insert it into the groove of the sash rail and turn the knob to securely lock it. It can be used on any rail if the width of the sash rail is 2.5cm or more and 4cm or less. Also, because it is made of iron, there is no need to worry about the lock being damaged by the impact of moving the sash. Made of metal and durable. Also, it comes with silicone, which increases friction and securely fixes it to the window slot without damaging the window.