Helly Hansen LIFA MERINO MIDWEIGHT 1/2 ZIP The men's functional T-shirt Helly Hansen LIFA MERINO MIDWEIGHT is a unique base layer with 100% merino wool in combination with Lifa® Stay Warm technology in a double layer design. It is ideal for any cold weather activity. It brings together all the great advantages of Merino wool fibres and the unique properties of technical fibres. Helly Hansen LIFA MERINO MIDWEIGHT 1\/2 ZIP