"This is an extractor top cap sight glass upgrade with a pressure rating of 125PSI. This unit is made entirely of stainless steel components with the exception of the Flare end cap for hose sealing purposes. The recommended applications for this unit is for a Closed Column Extractors and our Closed Loop Extractors. All fittings are 1/4NPT. The base cap is a 1.5"Tri-Clamp. There are no gaskets or clamps included with this item. This unit will benefit you by allowing you to know when the solvent has filled your material column or to know when the solvent has stopped flowing.