Stubby gas lens made in the USA comes with the O’ring groove cut in the threads so you can run either a glass using the o’rings . Or you can remove the o’ring and use the threads with ceramic style cups . These Fit all 17/18/26 and are the same lenses that are in the adapter kits ,.
These gas lenses are built with superior quality with stringent QC guidelines. The gas lens must be working correctly to utilize the potential of the cups. We have found that all gas lenses are not created equal and you will find poor performing gas lenses. It is good to swap out lenses if you start to see performance dropping from gas coverage