Great acceleration in "low gear" and screaming top end in "high gear". Reduces plane time. Optimizes fuel economy 6" pitch change is fully automatic. East shift point adjuster. LIKE NEW CONDITION SELL FOR 899.98 PROP NUMBER 48-8233510 21P 15p to 21p Great pulling power with a 15 pitch then it shifts to a 21 pitch for speed and to keep from over-revving. 3 BLADE SS PROP FITS 135-300HP AND MERCRUISER 15 SPLINE HUB. John