250ml Narrow Mouth Erlenmeyer Flask with Rubber Stoppers, Karter Scientific 213G20 (Pack of 8) Volume: 250ml, Height: 145mm (5.7 in), OD Neck/Bulb: 31mm / 81mm Rubber Stopper Size: #6 Material: 3.3 Borosilicate Glass Graduations: 25ml, 100ml - 250ml Single Metric Scale