Cooler brakes stop more reliably, and Shimano's Flat Mount L04C Metallic Ice-Tech Disc Brake Pads use both cooling Ice Technology and a metal construction to provide the highest all-around stopping power in Shimano's line.
On their own, metallics are reliably effective in wet or dry conditions, lasting easily twice as long as their resin counterparts. The pads' Ice Tech distinction refers to an additional radiation fin pad, made with an aluminum and stainless steel fin that improves the pads' ability to stay cool under hard braking.
If you're running Ultegra BR-RS805 or 105-level RS505 hydraulic disc brakes on your bike and want a go-to wintertime pad for wet, muddy and gritty conditions. This is the one.