Mishimoto XL Compact Catch Can Bottom (For Compact 2-Port & 3-Port Catch Cans)Need a little more space for blow by in your current catch can setup? With the Mishimoto XL Compact Catch Can Bottom you can now expand the capacity of your Compact Catch Can system. The 6061 aluminum catch can bottom is a direct match for your Mishimoto catch can and increases your capacity to 7. 5 fluid ounces. Whether your vehicle is producing more blow by than anticipated or you just want to increase the time between servicing, the Mishimoto XL