Overview The Ultralight Mid Sock is On's racing sock — an ultrafine-gauge yarn construction designed to feel like running sockless, with thick heel and toe padding and anti-blister patches where needed. Ankle coverage keeps dirt out on trail. Ultralight Mid Sock, ultrafine-gauge recycled polyamide, designed to feel like running sockless. Thick heel and toe padding, anti-blister patches. Inside the On range, Ultralight Mid is the race-day sock: ultrafine gauge to cut weight and bulk inside racing shoes, targeted heel and toe padding for shoes like Cloudboom Strike and Cloudboom Max, and a close, seam-minimised fit designed not to add friction over 42 km. Details Best for: Racing from 5K to marathon Hot-weather sessions Runners who want minimal sock feel Specs Fabric: Ultrafine-gauge recycled polyamide with elastane Features: Ankle coverage, thick heel and toe padding, anti-blister patches, snug toebox Colourway: White, Black Sizing: S / M / L Materials & Care Designed in Zurich. Machine wash cold with like colours. Do not use fabric softener. Tumble dry low or air dry. Do not bleach, do not iron. Anatomical L/R shaping may relax slightly after first wash, this is normal. Bundle & Save Build a bundle and save up to 10% off. Shop Bundle Builder
