UNITED SCIENTIFIC SUPPLIES Stopper: Rubber, 3 Stopper Size, 18 mm Bottom Dia, 24 mm Top Dia, 25 mm Overall Ht

This black rubber stopper (size 3, 18 mm bottom dia, 24 mm top dia, 25 mm height) seals laboratory flasks, test tubes, or bottles. The 2 holes allow insertion of glass tubing, thermometers, or probes for gas transfer or vacuum applications in chemistry and biology labs.

The RST3-H2 is a black rubber stopper, size 3, with a bottom diameter of 18 mm, top diameter of 24 mm, and overall height of 25 mm. It has 2 holes and is made by UNITED SCIENTIFIC SUPPLIES INC. The material is rubber, suitable for general-purpose laboratory sealing.

3G Electric supplies the UNITED SCIENTIFIC SUPPLIES RST3-H2 rubber stopper to customers worldwide. We handle full logistics, customs clearance, and delivery to your facility. Contact us for a quote and lead time on this lab consumable.

Measure the inside diameter of your flask neck. The stopper's top diameter (24 mm for size 3) should be slightly larger than the neck opening, while the bottom diameter (18 mm) fits inside. Ensure the stopper compresses to form a tight seal. For 2-hole needs, choose a pre-drilled stopper like the RST3-H2.