Seger Shs-Ski Mid 01 Sock. Heatable slipper sleeves with built-in heat from Seger, which are prepared to be used with the Seger Heat System. The socks can be heated with a battery. The Alpine socks are knitted in merino-blend with a little compression that is both durable and comfortable. Comfortable knitwear and minimal knitted stitch that provide good comfort.