Fabricated from borosilicate glass with walls tapered inward toward bottom to allow operation with smaller volumes. 250mL size supplied with #25 Screw thread center neck and three 14/20 side necks. All other capacities supplied with #36 Screw thread center neck and three 24/40 side necks. Use 7506-10 bushing and o-ring in #25 Screw thread 7506-12 bushing and o-ring in #36 Screw thread to form a leak-tight compression seal with all 9814 Horns with groove and 9852-41 or 9852-45 slide adapter. Stated capacity is WITHOUT horn. See horn selection chart, below, for proper horn size. Vessel NOT supplied with bushing or o-ring, order separately.