For processing samples with ultra low eutectic points. Secondary Trap connects in series with a freeze dry system and vacuum pump to prevent contaminants from migrating into the vacuum pump. After pulling a vacuum, liquid nitrogen may be introduced via the liquid nitrogen port. Liquid nitrogen cools to -196° C (-321° F) to trap contaminants with low eutectic points. The well may be defrosted and the liquid drained from the drain hose. Glacier white epoxy-coated steel construction. Two valves may be opened (trap) or closed (by-pass). Opened valves allow gaseous contaminants to be trapped in the liquid nitrogen well. Closed valves allow gaseous contaminants to by-pass the well during defrosting and draining. 3/4" OD inlet and outlet connections. Includes an insulated filler tube for connection to a user-supplied liquid nitrogen tank; 20" rubber tubing; 3/4" ID x 3/8" wall; and two clamps. Liquid nitrogen is required (not included).