THIS LISTING IS FOR ONE (1) 6" STEEL HUB FOR A WIND TURBINE OR WIND GENERATOR WITH AMETEK OR OTHER PM MOTOR OR PMA. IT USES AN AIR-X BOLT PATTERN FOR 2,3,4 OR 6 AIR-X BLADES. IT IS 1/8" THICK STEEL AND WAS PUNCHED ON A CNC PUNCH PRESS FOR ACCURACY IN AN AEROSPACE QUALITY MACHINE SHOP NOT SOMEONES GARAGE! CENTER MOUNTING HOLE SIZES ARE AS LISTED 1/2", 5/8" 17MM FOR PMAS OR OTHER PERMANENT MAGNET MOTORS, OR YOU CAN ORDER A CUSTOM CENTER HOLE SIZE FROM 1/2" TO 1"( WE DO CHARGE $4 MORE FOR THIS). THEY ARE IDENTICAL OTHER THAN THE CENTER HOLE. BLADE MOUNTING HOLES ARE 15/16" ON CENTER. THESE ARE UNPAINTED AND SHOULD GET A COAT OF WHATEVER COLOR RUSTOLEUM YOU LIKE. IF PAINT IS AN ISSUE CONTACT US TO MAKE OTHER ARRANGEMENTS. WE TRY TO ANSWER ALL QUESTIONS DAILY SO PLEASE FEEL FREE TO CONTACT ME. THANKS FOR LOOKING AND BE SURE TO SWING BY OUR STORE FOR OTHER COOL STUFF AND KEEP WATCHING FOR MORE WIND TURBINE/GENERATOR PARTS COMING SOON! THANKS FOR LOOKING AND HAPPYING!! RIGHT NOW WE ARE OFFERING FREE SHIPPING TO U.S. CUSTOMERS ONLY.