I found out from Aquatic Critter that they still have the clamp spacers for the Viper lights they sold at the swap off from their display tank. I think the lamps can be used without these, but they will probably help reduce the risk of cracking your tank by tighting down the clamp too much. All you have to do to get a pair of these (if you purchased a light from AC at the swap) is to stop by the store and ask for Chris. You can also call them if you don't live in the area and they will ship them to you.