A firm gasket based on Neoprene and designed for use in transformers and switchgear where high bolting loads are used. Whilst Nebar Red was intended for use with mineral oils, it has also been used successfully in silicone fluid transformers, although this would not be a general recommendation. Its special property is its ability to seal higher internal pressures than medium stiffness cork gaskets when high bolting stresses are used; this however is dependant on the flanges being sufficiently stiff to resist bending. This property also makes it suitable for use in general industrial applications where a neoprene/cork gasket is suitable and where significant internal pressures are involved. With a thin gasket and appropriate bolting and flange arrangement, internal pressures in excess of 20 bar can be sealed.