Unit Digital Ultra Clean Metal Seal Mass Flow Controller. 500 psi Max/3500 kPa. UNIT 8560 SERIES DIGITAL ULTRA CLEAN MASS FLOW CONTROLLER UFC-8565, AR GAS. We reserve the right to refuse any order you place with us. We reserve the right to limit or prohibit orders that, in our sole judgment, appear to be placed by dealers, resellers or distributors. All freighted items will be secured with protective wraps and packaging. Due to the nature of inventory, exchanges may not be available. Listing and template services provided by inkFrog.