OMS Isolation manifold for double scuba cylinders. This is a rigid manifold that will only accommodate 7.25" cylinders. Please see photo of measurement, I have not validated the size but based on other manifolds I have on hand, it would look like these are for 7.25" diameter cylinders (AL80's, LP85's, HP120's, etc). Manifold was in good working condition when removed from service, no issues... ready to install on a new set of tanks. Sold as is.
