The last photo above shows the Gator RC carbon tube and a couple different socket options. The black fiberglass (the lower tube) is the stock item that comes in the package. It weighs around 11 grams. The carbon tube (middle tube in the last photo above) is the stock item matched to the fiberglass socket. It also weighs 11 grams.
The top tube is a phenolic material that came stock with the aluminum tube. The phenolic weighs 9 1/2 grams.
The 1/32" balsa sheet lined with a layer of 1oz. fiberglass, weighs about 4 grams. It will be shaped around the carbon tube and will be used in the build. It makes no sense to use the stock socket materials when trying to remove weight from the structure. A balsa/glass tube is far lighter and strong enough. For wings too....