Theres no substitute for the Original Body Armor 4x4 Bumpers.
There are a lot of other manufacturers on the market these days, and they encourage you to learn the difference, The Road Armor difference, because not all replacement bumpers are created equal.
There is a simulated weight that attaches to your nock just the same as the lighted nock that will make all of the nocks weigh the same.
There is roughly a 23 grain difference when adding Firenock lighted nocks.
See below for routine maintenance tips and recommendations.