This is an IMPERIAL 2 Piece Wet Suit.  It has a Jacket and Pants.  It is Black with a "textured" exterior.  The inside is blue.  It is 90% Neoprene and 10% nylon.  There are pads on the elbows, knees, and a long one on the back for a Scuba Tank.  This can be used for scuba diving or snorkeling.  The jacket has a heavy duty zipper and two clasps to help keep it in place.  There is a tiny pocket on the inside of the jacket. 

I took a lot of measurements so you could see actual sizing.  Heavy Duty to keep you warm in the water.  Real Nice diving gear...no rips or tears.    Comes from a smoke free home.

More information:

This is a Imperial Turtle Nylon one wet suit Bremerton Washington.  From the logo/font used it is probably late 1969 early-mid 1970s and was top drawer from that time period, the edge stitching, added small inside car key pocket, spine pad, elbow pads, knee pads and premium nylon YKK zipper.