This lock is made for jewelry,its already proven the effectivness, you have 11 x 4.30 mm long and wide ,the weight of this product is 0.90 gram , is checked ,tested and you have several formats of files like 3dm,stl,obj,blend. you have to put the steel 0.30 mm in it and thats all.
PS/ the steel that i made in the picture its only a sample,
enjoy .