Slightly lighter and thinner than the fleece-lined swimwear but nonetheless still effective at helping to maintain core body temperature when worn snug. You would know neoprene as the material popularly used to make adult surfing wetsuits.
Made of 2mm thick neoprene so they keep warm without being uncomfortable, stiff or too buoyant. Comes in half sleeves (Warm Kinetic) and full sleeves (Warm KineticX) styles. Zipper cords are available for Warm KineticX styles sized 4y and above.