The unique design of the Van Alstine blade includes a tapered shape making the blade wider near the top where strength is needed and thinner at the bottom, greatly reducing drag as the blade cuts through the rubber. The highly finished cutting edge combined with the tapered design results in a blade that cuts cooler and is unmatched in performance and durabilityHigh quality Van Alstine razor sharp blades are available in a wide variety of cutting widths in both flat and round bottom styles. Blades are designated with either a "GF for flat bottom or a "GR for round bottom. Blade sizes correspond to thirty-seconds of an inch in width. A #6GF blade cuts 6/32 wide and has a flat bottom. A #6GR blade cuts 6/32 wide and has a round bottom.