IF YOU HAVE A COX .049 ENGINE LAYING AROUND WITH A BURNED OUT GLOW HEAD AND YOURE HAVING TROUBLE FINDING A NEW ONE THEN TRY THIS. DRILL A HOLE IN THE CENTER OF THE HEAD AND TAP SOME THREADS IN IT THEN SCREW IN A O.S.-A,3 GLOW PLUG AND IT WILL RUN LIKE A TOP I MUST SAY I WAS IMPRESSED WHEN MY SON DID IT AND IT WORKED SO WELL . I JUST THOUGHT THE ENGINE WAS READY FOR THE BONE YARD.