The Kaydon Filtration Model 825-2 Overflow Sight is an accessory item used with offline (kidney-loop) oil conditioning systems, such as a Turbo-TOC®, to maintain a fixed level of oil in oil reservoirs used for circulating oil lube systems. The 825 is mounted on the suction side of the oil conditioning pump, near the oil reservoir, and helps prevent accidental draining of the oil reservoir. If oil level drops below critical oil level, the 825 serves as a “siphon break”, preventing the oil conditioning system from pumping additional oil out of the oil reservoir. The 825 serves as a mechanical method of maintaining desired oil level in a reservoir in conjunction with the oil reservoir electrical float level switches. The 825 adds an additional level of “anti-drain” safety.