Designed for warm days on the river or days spent on the flats, the Korkers I-drain 2. 5mm Neoprene Wading Sock keeps your foot comfortable in your wade boot without you having to wear your full waders. The 2. 5mm thickness maintains the same fit inside your boot, while the neoprene stretches to conform to your foot's unique shape. Underfoot, perforated Airprene material allows any water to drain out--keeping your foot from becoming heavier as the sock takes on water.