United Scientific® Solid Glass Pennyhead Stopper, 24/40 Ground Joint – Borosilicate Tapered Plug for Lab Flasks and Glassware

The United Scientific® Solid Glass Pennyhead Stopper with a 24/40 ground joint is a precision-crafted solution for securely sealing laboratory glassware. Made from durable borosilicate 3.3 glass, this pennyhead stopper features a solid plug with a closed bottom and vertical head for easy insertion and removal. Designed to fit standard 24/40 taper ground joints, it offers excellent chemical resistance and thermal stability, making it ideal for use with flasks, cylinders, funnels, and other lab containers. Conforms to ASTM E438 Type 1, Class A specifications for high-quality laboratory performance.