Built to deliver superior cold-weather traction, Glacier Trek SPK overshoes feature multidirectional lugged outsoles that dig into ice and snow with ease to give you sure footing on slick winter surfaces. Note: For the best fit, measure the outsole of your footwear and then compare with the inside dimensions of overshoes. The manufacturer recommends going up one size when wearing safety footwear or up two sizes if boots have a toe bumper.