Thingymabob chains end with a lobster clasp clip making the weights interchangeable.
"What if I'm not sure what size weight I need?"
We suggest the more active you are the heavier the weight. BUT weight depends on each individual's own comfort, and I was surprised to find out myself how light I like my own. So if you are new to thingymabobs we suggest buying the sphere cages also pictured with every chain, they are too light on their own but allow you to change the weight by caging crystals, dice, and other small trinkets.