These adult and adolescent models are made of durable plastic with rust-resistant skeletons, articulated joints, and optional CPR capabilities. As the manikins fill with water, they will sink up to the neck. To take them to the bottom, add five to ten pounds of weight (not supplied). A brick will do. Used by American Red Cross, US Coast Guard, Sheriff’s Department, Lifeguard Trainers, and Emergency Personnel these manikins are excellent top and bottom water rescue devices for adding the shock of realism to an otherwise ordinary practice procedure.