The DGX triple O-ring seal replacement kit comes with 3 O-rings, suitable for use in the DGX 600, 700, 800 and PUSH lights. ​Remove the old o-rings, clean the o-ring grooves in barrel and the sealing surface on the opposing face of light head, then apply a small amount of any common lubricant used in SCUBA such as silicone grease to the o-rings and sealing surface.