Ref - L-OS71605200 -
OS engine specialist cool glow plug is recommended for the Wankel Series and has found use in other areas where high nitro is being used and a cool plug is needed to prevent blown glow plugs. If you have a piped engine that is eating up your usual plugs. Try an R5.
Glow plugs are considered to be consumables - But by using a low voltage to start ( under 1.5 volts) and not burning the plug dry, you prolong the life of your glow plug. It is also worth washing out a new engine after running in to prevent small particles shorting the plug and destroying it. Blowing plugs on new engines is less common now a days, but is still something that can happen.