Elaflex couplings type MK100. Manufactured acc. to DIN 28450/EN 14420-6. Material: Brass. Seal: Generally, in brass couplings, seal VD are always used as seal for thread and seal type PD as seal for coupling. In stainless steel couplings seal TD are used as seal for thread and seal HYD as seal for coupling. PD = Nitrile (Perbunan). VD = Vulkollan. TD = Teflon. HYD = Hypalon.