When I first purchased my Dangerous Power Threshold I was a bit confused because my manual said that I couldn't use regular marker oil. It stated that I was required to use Dow 55 lubricant. The 55 stands for the viscosity of the lubricant. For those of you who who don't know viscosity is kind of like the thickness of the lubricant. Anyways as I was saying when I looked for that kind of lube I couldn't find it so I called Dangerous Power and they said that you can use the SL33K lube by smart parts as long as you clean your gun often and you can use oil in the R.A.P.S if you only use like one drop.