Borosilicate glass, round bottom reaction vessel. Supplied with 24/40 center neck and two 24/40 side necks. Fourth neck is #25 Ace-Thred on 500 mL for use with 7506-10 Bushing and O-Ring; #36 Ace-Thred on 1000 mL and 2000 mL sizes for use with 7506-12 Bushing and O-Ring to make a leak-tight compression seal with all 9814 Horns and 9852-41 or 9852-45 slide adapter. Center neck can be used for mechanical stirring if needed. Stated capacity is without horn. Vessel not supplied with bushing or O-Ring, order separately.