DonFiber ST Type I High performance steel fibers with hooked ends for reinforcement of concrete and mortar (Formerly known as ST Fiber Type 1) You might also be interested in DonFiber PP Macro X High-performance macro polypropylene fibres for flooring applications DonFiber PP-M High-performance monofilament polypropylene fibers DonFiber PP Ultra Ultra-fine, high performance monofilament polypropylene fibers DonFiber PP-F High-performance fibrillated polypropylene fibers