Nalgene 4 mm diameter syringe filters (CA, Nylon) are designed to filter 0.5-1.0 ml. Nalgene 13 mm diameter syringe filters (PES, PTFE) are designed to filter 2-10 ml. Nalgene 25 mm diameter syringe filters (PES, PTFE, Nylon, SFCA, CA, and glass fiber