Rubber Stopper - 1 Hole

These one-hole rubber stoppers, also called rubber bungs, are made from chemical-resistant natural rubber with a single hole through the centre for a glass tube, thermometer or pipette. They come in packs of 10, in sizes from 5mm up to 51mm across the bottom.

Sizes are given as bottom diameter x top diameter x length, in millimetres. To choose one, measure the inside of the neck you want to close. The stopper should be narrower than the opening at the bottom and wider at the top, so it wedges in and seals partway down.

For a round bottom flask with a 19/26 socket, use RS9-1H. For a 24/29 socket, use RS13-1H.

Available sizes (pack of 10)

• RS1-1H: 5x7x16mm
• RS2-1H: 6x9x16mm
• RS3-1H: 8x10.5x20mm
• RS4-1H: 9x11.5x20mm
• RS5-1H: 10x12.5x20mm
• RS6-1H: 11x14x24mm
• RS7-1H: 13x16x24mm
• RS8-1H: 15x18x24mm
• RS9-1H: 17x20x26mm
• RS10-1H: 18x21x26mm
• RS11-1H: 19x22.5x28mm
• RS12-1H: 21x24.5x28mm
• RS13-1H: 23x26.5x28mm
• RS14-1H: 25x28.5x28mm
• RS15-1H: 27x31x32mm
• RS16-1H: 29x33x32mm
• RS17-1H: 31x36x35mm
• RS18-1H: 33x38.5x38.5mm
• RS19-1H: 35x45.5x36.5mm
• RS20-1H: 38x42.5x40.5mm
• RS21-1H: 40x49.5x40.5mm
• RS19-1HL: 35x28x36.5mm
• RS22-1H: 44x58x48mm
• RS23-1H: 48x53x34mm
• RS24-1H: 51x60x57mm

Need a stopper without a hole? See our solid rubber stoppers.