QUICKFIT® hollow-blown glass stoppers (B length) with a hexagonal top and drip tip. Stopper taper complies with ISO 383 and the borosilicate glass meets ISO 3585 (ASTM E-438 Type 1 Class A). Lightweight hollow-blown design, anti-roll hex head for improved grip, and a flat/slightly concave top so they can stand on end to help keep the ground surface clean. The drip tip directs any liquid back into the flask.