Rcexl 5 cylinder ignition system with pick up and magnetic ring design for an OS FR5-300, 5 cylinder radial engine. I have attached prop drive hub dimensions the magnetic ring fits onto. I have also included 5 x 1/4" -32 sparkplug and Rcexl Opto Gas engine Kill switch. I have tested both the ignition system and kill switch and both work. I bought this ignition system with an unused pre owned engine. please contact me if you need more information.