This monster bag is made out of a bicycle inner tube. He has double sided velcro straps on the back so he can ride on your bike with you. I put a window in him so you can see what's inside. He has safety eyes and a zipper for a mouth. I gave him a little felt tongue, but don't worry, it won't get stuck in his teeth. I made him big enough to carry a small cell phone, keys, ID, cash and other small items. He measures 3.5"x5.75" (8.9cm x 14.6cm) the velcro straps are 6" (15cm).