Tunze Coral Gum Instant 104.76 is a two-component coral adhesive for the safe cementing of coral fragments to stone substrates. No deleterious matter or adhesive residue is introduced into the aquarium water; it is unbreakable, yet remains flexible and withstands high loads. Can be used in freshwater and marine aquariums. Contents: 2 x 200 grams (14.11oz.). Instructions For Use.