Featuring elastomer seal and metal seal, respectively, Brooks GF40 and GF80 are suitable for customers who use variety of gases and need to change gas types frequently, or who need to re-range while preserving gas measurement and controlling accuracy. Thermal mass flow controllers and meters are equipped with corrosion-resistant Hastelloy C-22 sensor. Units provide full scale flow range from 3 sccm to 50 slm with linearity of ±0.5% FS and flow accuracy of +1% SP 35–100% and +0.35% FS 2–35%.