All-metal self-supporting design accepts any shaft. Fletch straight, offset, true right helical, or left helical. Permanent magnet ensures precise placement. Self-centering nock receiver is adjustable for 3-fletch 120°, 4 fletch 90°, or 4 fletch 75° x 105° spacing. Includes clamp, instructions, and wrenches. Optional nock receiver available for 3 fletch 120° cock vane down.