Penetro 90�� is a high-performance penetrating oil that lubricates all types of moving parts that have become difficult to operate. Penetro 90�� is oil based and blended from our patented formula of penetrating oils and three different types of rust and corrosion inhibitors. This unique blend allows Penetro 90�� to penetrate deep into the pores of metals, and cover surfaces with a light, clear lubricating film with lasting staying power. When sprayed onto rusty bolts, Penetro 90�� coats each rust particle and acts like tiny ball bearings, allowing the rust particles to easily slide over each other.