My R65 was fit for dual plugs by the previous owner. I want to check that they are extending the right amount into the cylinder. Options include $20 USB scope or a telescoping mirror. I don't want to take the jugs off. http://www.ebay.com/itm/6-5Ft-2M-US...363?pt=LH_DefaultDomain_0&hash=item5898e8df2b http://absupply.net/brooks-im-inspection-mirror.aspx Thoughts?