#6.5 (6 1/2) stopper - with 3/8" hole for an airlock. Top diameter 1.34 inches (34 mm), bottom diameter 1.06 inches (27 mm), length 1 inch (25 mm).
This BPA-free stopper is made of food-grade materials. Injection molded TPE for superior consistency throughout. Perfect for use with carboys, as the material sticks well to glass and PET, even when wet.
Maximum temperature rating: 158 °F (70 °C)
It fits many glass carboys, as well as our 250ml Erlenmeyer flask.