The Aqua One Aqua Lube Silicone Lubricant helps extend the service life of O-rings, seals and moving parts within aquarium equipment. Rubber seals and O-rings lose their suppleness and elasticity over time and with that the ability to provide a 100% water-tight seal. This elasticity can be regained with the use of the Aqua Lube Silicone Lubricant to ensure good flexibility and in turn an improved sealing function.