Perfect for your material columns or collection vessel, these 6" Tri-Clamp sight glasses are perfect for pouring out your run or viewing your solvent in action. Butane or propane extraction, this sight glass spool is ASME stamped and rated to 350 psi and -80c. Extract with safety knowing your 6" site glass spool is safe for your LPG extraction. These spools are 6"X6" and are the perfect fit for your butane or propane extraction system.