If you are missing bumpons or screws from your Corne-ish Zen, place your order here for replacements. Screws are sold in packs of 5, bumpons in packs of 4.
R3 keyboards do not require these resistors... they already have them.
If you would like to attempt to replace your (R1 or R2) USB resistors to ones with the correct value, you can also select them here. Selecting the resistor option will provide you with 6 resistors (only 4 needed to fix)