By all mean i copied it from troy and a couple of the other guys. You can get the neodine magnets pretty cheap i think i got a pack of 100 for $5.00-$10.00 It wasn't enough for me to even note. just bum around ebay They come in all sizes Mine are to big for the roadwheels butwork for just about every else. I'll take some measurements for you and a pic or two for reference.

Bill