Description

Best quality red rubber.  Shore hardness in range 46-55.  Bottom diameter moulded on top face.  Resistant to dilute acids, alkalis and ammonia.

Bottom Diameter: 31mm
Top Diameter: 36mm
Length: 35mm
Temperature Range: -30°C – 70°C
Hole Diameter: 5mm
Pack of 10

Size 31 stoppers are ideal to use with Economy NM Flasks 100mL, Pyrex NM Conical Flasks 250-500mL and Simax Side Arm 250mL.
Please note: Extreme care must be used when inserting glass into the holes in rubber stoppers.