Filter inside low flow modules 800518 & 800519 Back Catalog number: 201119 Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 811-0012-01 Gilian 800i/5000/10i/12 Replacement filter, pkg 10 Price on request 783-0013-01-R Battery Pack AA Alkaline Price on request 801012-100 Aircon-2 DC Programmable Area Air Sampling Pump, ( Price on request