1/4 Brooks Mass Flow Controller. New (other) Surplus, Excess Inventory. Located at Bitter End Trading LLC in Springfield, NH. Listing Includes Only What is Shown in Pictures See Pictures for Information! Bitter End Trading is an asset recovery wholesaler specializing in new and used surplus industrial equipment. All items listed are identified as either new or used and the new may be older surplus. We list all items to the best of our ability and aim to provide the customer with as much information as possible. No warranties are expressed or implied. See individual item for cost. All items are palletized and shrink wrapped before they leave the warehouse.