Bob Long VIS/SC Donut Replacement

Getting a little hiss down the barrel of your VIS/SC engine? Then you're probably due for a new Donut. These will be sold in packs of 3.

New Donut Features: 

• Improved material choice for better sealing characteristics 
• Front Stabilization O-ring 
• Modified Face geometry to assist in sealing

Note: Since these engines varied drastically in terms of tolerances, some initial shots might be required to allow the Donut to fully seat. When installing the Donut, please ensure the seals are facing towards the front of the Marker.