Boyesen 606 Power Reed For: Honda CR125 1978-1992; Suzuki RM125 1987-1988; Suzuki TS125R all models; Suzuki TS200 and TS200R 1992-1993; Yamaha DT250 1974-1975, DT360 all models, DT400 1974-1975 For: MX250 all models, MX400 all models, MX500 1973, SC500 all models, XR500 1982, YZ250 through 1977, YZ360 through 1978 and YZ400 through 1978 The top reed is lightweight and resilient for crisp throttle response at partial throttle or low RPMs; the stiffer, bottom reed is ported to provide maximum flow and horsepower at higher RPMs Longer overall life: Boyesen power reeds outlast all other aftermarket reed petals Power reeds use a patented dual stage fiberglass design for more air flow, more air velocity and more power; minor change gives major horsepower improvements and fuel economy