3 mm neoprene, watertight stitch-bonded assembly (GBS)
3 mm neoprene.
The seams of the gloves are waterproof due to GBS assembly (Glued and Blind Stitched): The neoprene is glued first, then stitched for maximum strength (the needle does not completely pass through the neoprene to prevent water infiltration).
The palm of the hand is reinforced with Supratex for added grip.