The All steel STR from Trailer Master is a trailer tire that utilizes a closed shoulder design to reduce uneven wear for a longer tread life. Four wide grooves force water out of the tire to reduce the risk of hydroplaning, and the All steel STR’s construction enhances load carrying capacity and durability. Designed for use on trailers Closed shoulder design reduces uneven wear for a longer tread life Four wide grooves in the tread force water out of the tire to reduce the risk of hydroplaning Tough construction enhances load carrying capacity and durability