Tool: stirrer for processing rubber. Rounded aluminum rectangle with three holes down the center. Used to mix acid with and stir latex. Used after adding acetic acid. Any suitable material may be used including tin, wood, plastic, etc. Each person fashions his own stirrer from whatever material he has handy, made in a wire range of designs. Used by all people. Cost in U.S. dollars: 21 cents. Length 17.5 cm. Width 11.9 cm.