LAPP SKINDICHT® MR PG Series Reduction Rings - LAPP 52003840, The SKINDICHT® MR is a nickel plated brass reducing ring with PG threads in accordance to DIN 40 430. The reducing ring is used if threaded holes are already present, on machines or equipment housings, but are too large for the necessary glands. LAPP 52003840 SKINDICHT MR PG 16/13.5 Reduction Gland