Includes enough o-rings to rebuild your Empire BT-4 paintball marker 5 times! Also includes a compartmentalized carrying case to store and organize your o-rings. Our Color coded o-ring kits make maintaining your marker easier than ever! After the initial installation, if an o-ring happens to break or wear down, you just need to open your boxed o-ring kit, and pull out the o-ring of matching color and swap it out! No more measuring. No more comparing stretched, used -rings with pristine new o-rings. No more sizing charts; no more headaches. Spend less time in the staging area and more time on the field mowing down the opposition!