Keystone Mainspring Lubricant Light is light only in its viscosity, which is often used for smaller clocks. Withstands pressures of over 300,000 Psi. Keystone Mainspring Lubricant Light outstanding film strength allows mainsprings to release with smooth and even power for years without binding, rusting or galling. Keystone Mainspring Lubricant Light displaces moisture caused by insufficient drying or high humidity conditions. Stays where it's put. Contains no graphite or sulphur.