Brooks Instruments 4850ABB1B1B1GQB00A Mass Flow Controller 4800Series NEW. New Brooks Instruments 4850ABB1B1B1GQB00A Mass Flow Controller 4800Series as shown in the pictures. Please be sure to check our store for more Surplus items. By purchasing from Hadalgo, you agree to these terms. We highly recommend UPS Standard to Canada as it is a much cheaper alternative to UPS Worldwide. Database glitches resulting in underpriced surplus.