dUNE HAS A POINT ABOUT GAMBLING ON 200 DOLLARS. mY ENDCAP MOD MAD AS MUCH POWER AS MY HMF. i DON'T HAVE A SPARK ARRESTER ON MY HMF BECAUSE i PUT THAT MONEY TOWARDS SOMETHING ELSE. i USED STEEL WINDOW SCREEN. i JUST TOOK A PAIR SCIZZORS AND CUT OUT AN FOUND CIRCLE THE SISE OF THE REMOVABLE END CAP AND BOLTED IT BETWEEN THE END CAP AND PIPE. i HAVE PASSED OVER 8 INSPECTIONS. i ALSO WORK FOR U.S FS SO i THINK i WOULD KNOW WHATIT TAKE TO PASS AS A SPARK ARRESTOR.