This is for a brand new  
Brass 8x1mm Prop Spinner Nut with a 5/8" hex.
Weight is 23.1 grams
Not a common size --- Check your engine.

This is the size used on larger
 glow engines is a special size.

Check our store listings for
different thread and hex sizes.

THE CHART BELOW SHOWS THE OTHER SIZES MADE BY MECOA K&B MFG