Prevent solids from plugging the tip of pipet when sampling liquids that many contain solid particles. Half of the sleeve is made of the same filter material that isused in the Whirl-Pak filter bags and the other half is solid 3.0 mil polyethylene. The pipet slides into the sterile sleeve and is inserted into the liquid to be tested. The liquid passes through the filter, but not the solids. The sleeve is sized to hold up to a 10 mL pipet. 25 per resealable package. 500 sleeves per box.