hello this is the 2nd one I've done of the bow, and I've added some things to it to make it better and more fun by adding a harpoon attachment and a notch on the arrow. Also the right size needed for the nuts and bolts are 4m 6-32 stainless-steel nylon lock nuts (8 count) and stainless-steel pan Philips machine 6-32 x 1-¼ 4m bolts (8 count) + I used a nylon cord as the string. (I found them at Lowes) I hope you enjoy! just don't hit anyone!