Hot Sockee Toe Warmers designed to go over your favorite sock and inside your shoe or boot. Thin enough for a comfortable fit, thick enough to provide that extra layer of insulation to get you through the coldest and freezing wet days. Concentrates insulation benefits over your toes where you need heat without leaving your foot soggy. Stays in place inside your shoe. Brilliant for MTB riders especially if using flat pedals. Winter cyclist appreciate insulation benefits between foot and cleat for extreme cold climates. We selected the material thickness, toe shape and stitching design to offer comfort and maximize heat. Insulation is provided using neoprene just like a wet suit. Excellent in any type of work boot for warmer more comfortable day. Maximize heat from electric foot warmers. Many people use air activated chemical toe warmers with Hot Sockee to maximize their heating benefits. CUSTOMERS SAY ALSO GREAT FOR Ice baths, mitt style gloves for hand warmers and insulation for the hands. To be worn inside shoe, no strap needed, .Foot protection in swim, dive and boogie board fin\'s, anti-chaffing. DETERMINE YOUR SIZE: 1- Measure foot width at widest point. 2- Look at size guide image. Shoe size is a SUGGESTION as the Hot Sockee has no heel (open length). For best fit Measure foot width at widest point. Size up if between sizes or have a wide foot. Hot Sockee is very versatile and can offer insulation and sustain warmth in various shoe / boot and sock combinations. Size SUGGESTION by Shoe Size - MEASURE FOOT WIDTH, refer to fit chart in images for best fit: S/M (3 3/4 Width) | Men 5-8 | Women 4-7 Large (4) | Men 9-11 | Women 8-11 XL (4.5) | Men 11+ | Women 11+ see images for full dimensions. MEASURE YOUR FOOT WIDTH