Over 20 years ago, BLACK GOLD Pump and Supply engineered and designed the full-open Nylon Insert Cage. The full-open Nylon Cage's unique design allows the life of the cage to be tripled in almost all cases. The full open Nylon Cage is made of soft material which allows the ball to bounce off the nylon; without damaging the cage, or the ball.  The full-open Nylon Cage is corrosion resistant, acid resistant, solvent resistant, and can withstand the heaviest of abrasive materials; like sand, scale, and trash. The melting point of the full-open Nylon cage is 250 degrees, operating temperature. All Nylon cages are available in the following sizes: 2 ¾", 3 ¼", 3 ¾", & 4 ¼". Upon special request, we can make the full-open Nylon Insert Cage in all pump sizes.