The OPECL series of products, type TOM-500 and TOM-1000, are designed for automatic adjustment of the optimal oil lubrication level within a bearing housing, gear box, crank case or similar oil bath application. They effectively solve the problem of adjusting the correct oil level during running conditions rather than during stand-still. Furthermore, they will automatically compensate for oil leakage and offer the possibility for visual inspection of the oil level. The oil leveller will not compensate if the oil level is too high. The oil leveller basically consists of two communicating oil reservoirs, one on top of the other. The lower reservoir is in direct contact with the application and hence it&＃039;s oil level is the same as the oil level inside the application. Through a ventilation tube the lower reservoir is in direct contact with the ambient air.