All of the following are sterile Vacumed® devices made with Lithium Heparin. Each has a green cap. Models 42310, 42311, and 42312 all measure 13 x 75 mm. The first holds 2 ml., the second holds 3 ml., and the third holds 4 ml. Model 43316 measures 13x100 mm and holds 6 ml of blood.