"FP-10" has been claimed to be the same as 10 pt's rail lube. Danny Miller, USA warranty rep for Excal advised me and others not to use anything, wax on serving, rail lube, nada. Can't say as I can tell a difference, except on my Emax, a notorious serving eater, lol. His claim is that the wax/lube softens the serving, which allows the "claws" [holds string cocked] to eat the serving prematurly. I've settled on: nothing til serving starts to show signs of serious wear, then light waxing, mostly so I don't have to look at frayed serving, lol. Have fun!!