This is a linear bearing carrier for my Helical Bearings (https://www.thingiverse.com/thing:3098493), they will not fit the stock LM8UU bearings,or Igus Drylins. They might fit other helical bearings, but I make no guarantees.
With the helical bearings installed, they will save a lot of weight on your x and y axes, reduce noise, and wear on your rods.
For Igus Drylins, use this: https://www.thingiverse.com/thing:2781966
Print with the end with the thicker internal ridge on the bed, the stl file should be correctly oriented so you shouldn't have to rotate it.
You'll need 4x M4 half-nuts (sometimes called 'thin nuts' or 'lock nuts'), although regular M4 nuts will fit. So you'll need 16 for the y axis, and 12 for the x axis, so 28 if you plan on replacing X and Y bearings.
To fit the helical bearings, simply push them in from the end with the thin inner ridge, the top as it should be printed.
They can then be fitted to your printer.
My other Anet A8 upgrades can be found here: https://www.thingiverse.com/FredGenius/collections/anet-a8-upgrades
As always, your feedback is welcome!