The Mares Apnea 50 Instinct Jacket is a 5mm jacket with an integrated hood and open cell internal lining to keep you warm in colder waters. The Instinct has excellent elasticity, high thermal properties and is also compression resistant so you can move and keep warm at any depth.
The internal lining is a fragile open cell neoprene that is excellent at trapping water and keeping you warm.
The 2 part nature of the Instinct suit mean that you have extra thermal protection over your core as the jacket covers your torso down to your hips with a beaver tail crotch.