8% Milk Test Bottle (1) Gerber Cheese Test Bottle (1) Gerber Skim Milk "Double Quantity" Test Bottle (1) Replacement Solid Rubber Stopper: For use with the side-arm skim milk bottle. Double conical shape. (1) Replacement Stopper Set: Small & Large (1) Skim Milk "Side-Arm" Test Bottle - supplied with stopper (1) Small Stopper for 1021-01 Kit (1)