Eriez-Erie Stainless Steel Liquid Line Ferrous Trap Inline Magnet. Model: B-3. Material of construction: 316 stainless steel. The model B-3 ferrous trap provides magnetic protection for liquid lines and processing equipment by removing small particles of magnetic scale, rust and fine iron contamination during processing and is ideal for liquid purification or a variety of wet-separation applications. (5) 1 in. dia. x 7-1/2 in. L inside magnets. (2) 3 in. s-line pipe connection ports. Overall dimensions: 1 ft. L x 8-1/4 in. W x 10-5/8 in. H.(ACN29).