Safety bulb gives the necessary suction to fill average glass and plastic pipets. Mouth pipetting is eliminated. Bulb is squeezed and touched to the back of the pipet to draw up fluid. Remove bulb and control fluid level with index finger. One bulb will fit all size pipets. Included is an autoclavable elastic wristband. Red. 40ml. Dimensions (Dia.xL): 41 x 107mm.