Syringe filters for aqueous solutions are available in diameters of: 4mm, 13mm, 17mm, 20mm, 25mm, 30mm, and 33mm . Here’s a guide to help you choose your syringe filter size: 4 mm filters – for small volume samples less than 1 ml. 13 mm filters – for sample volumes between 1 and 10 ml. 17 mm filters – for sample volumes greater than 10 ml.