The spring at the beginning of the foam gun which mixing round the pu foam for better effection and more durable use for the usual foam gun,the spring always broken first, it is our patent design. Patented ategonomic design unmber : 200630114883.5 Features: 1) Aluminum plated brass body 2) Stainless steel needle 3) Teflon coated 4) 185mm in length 5) Gross weight: 385g 6) Teflon valve 7) Individually tested Packing: 20pcs/ctn Carton dimensions: 59 x 37.5 x 27cm Qty/20' FCL: 9,320pcs