Your marker can fire thousands of rounds every week, puts up with the beating of countless rainy Sundays, and withstands a number of slides through the dirt and mud. Through all of this, you still expect your marker to perform week in and week out. A small bit of maintenance is key to ensuring that your marker functions and performs at its best. One major aspect of marker maintenance is replacing your o-rings. The o-rings in your marker wear down over time by withstanding thousands of cycles along with coming in contact with dirt/debris. Our kits provide an easy and inexpensive way to keep your marker in top shape by swapping out your worn o-rings. Use our exclusive o-ring placement lists and color o-ring schematic guides, which shows drawings of your marker showing what o-rings go where. Rebuilding your marker couldn't be easier!