I found these lures to fit my Yihua 8786D (which uses 900M lure) without modification. I have also found that with a little touch up on the edge of the file I can get M3, M4 and M5 inserts to fit perfectly. The bar on the M3 tip only needed to be reduced slightly to fit the M5 inserts. This allowed me to take an M5 tip and scale it down to M4. This allows me to cover my 3 most used inserts with a snug fit for better heat transfer.