Heathrow Scientific HD20630D Bulb, 2-1/8" Outside Diameter x 3-1/4" Length, Rubber, For Large Pipette and Syringe Rubber bulb for large pipette and syringe Contoured shape and heavy-wall neck increase grip for easier use with pipets and syringes Capacity 60 milliliters Opening diameter 1/4" Measures 2-1/8" outside diameter by 3-1/4" length