Tunnel Tarantula wheels for Tunnel .70mm/78a. The “STR” - Speed Through Research - urethane formula optimizes the performance of the off-set, 70 mm wheels. In other words, these wheels are fast! The design and development of the Tarantula wheels and the new urethane compound has been a collaboration of many dedicated people. Mike at Tunnel, founder Mitch Haake, and the wheel and urethane experts at AEND Industries have all had a part. In addition, Oregon’s Longboard Larry and his racers as well as Canada’s Lee Cation have done testing and added input. The Racing Tarantulas are poured in 78A STR racing urethane with an eye-grabbing red and black swirl.