This is a spacer for the John Deere LA105 rider mower. The LA105 has a height adjustment on each side. You have to print 2 of these to use. This spacer is used to raise the cutting deck height higher. You can use PLA but I used PETG for the temperatures here in Florida. PETG is a lot stronger than PLA and won't warp in the high temperatures as much as PLA. It has holes in it to install a screw (you can use a 5mm or slightly larger) and nut (if you prefer). I used 100% fill to make it stronger. The support needed is for the screw holes to come out circular while printing. Now I get a cut that is a little over 5 inches instead of 4 inches.
You can use any percentage of fill. I chose to use 100% to make stronger. I also used support for the screw holes so that a decent circle would be printed.