50 * 50mm PTFE (Teflon) Back Catalog number: 8644T-50 Manufacturer: Sampling Systems Availability: In the manufacturer's stock Price on request - + Recommended 8700B-12 200mm Sieve. 150micron Price on request 8644AB-100 100 * 100mm Borosilicate glass (pyrex) Price on request 8700S-14 200mm Sieve. 106micron Price on request