The operation of opening the fastener is rather complicated, and it may be difficult for children and elderly people. Quick Free is a design to improve operability, leading to build confidence that children can do it by themselves. Specifically, by changing the shape of the top and bottom of the slider, the position where the pin (insert pin) is inserted becomes easy to see. The insertion port area is 3.18 times wider than the conventional product, so pin can be easily inserted to the port. Also, using the resin material for the slider instead of metal, we created the additional value of a releasing function when a load is applied to the left and right by taking advantage of resin's soft and flexible characteristics.