This chain is a little spin off of the well loved Barracuda Chain. So to add to its versatility we came up with the option to move where the heart design and where it rests in the chain. Center Fit sounds just like it is…the 5 hearts will rest directly in the middle of the chain. The Side fit option is just as is. The 5 hearts will rest to the side of the chain. It will work for either side needed by flipping the chain.