BUTTERFLY TIMO BOLL ZLF. The Timo Boll ZLF features the use of Butterfly’s newest ZL fiber. ZL fiber is harder, more flexible, and lighter in weight than carbon fiber. This results in a light weight blade which can produce a maximum amount of topspin with maximum control. The Timo Boll ZLF is the perfect blade for the all-round looping style with amazing feel through each shot.