Fidget Clicker is different to similiar products because of its unique peg. This means that the two pieces are less likely to come apart and makes for more repeatable fidgeting. Fidget Clicker requires 5mm x 5mm and 2mm thick magnets. The program will automatically stop part way through to allow you to place the magnets inside. Please make sure all the magnets are facing the same way. This fidget is great for subconcious fidgeting as well as relieving stress it always has the same satisfying click. Happy Printing.