5mm neoprene.
Perfect for integrating with dry suits, this is a top-quality hood for serious divers.
Features include:
Made from tough high quality 5.0mm "CR" neoprene. NOTE: be wary of buying hoods made by "SVR" (polyester) neoprene which is cheaper but is not as durable, or as warm as "CR". "SVR" is also highly flammable!