TrackStar glow plugs are an affordable yet quality product manufactured in Taiwan. TrackStar Turbo glow plugs are specially shaped to provide more efficient and powerful running of your nitro engine. They are ideally suited for 1/10~1/8 scale RC cars. At this price you can stock up your starter box and never be without a spare plug again!
Hi Malcolm, the OS A3 plug is normal plug with your OS ld15 engine.
this TrackStar is "Turbo" Plug, you can not use.
you can check another page TrackStar 1/10~1/8 Scale Glow Plug No.3 (HOT)
PRODUCT ID: 922000019
this one is exactly you need.