Bicycle Vintage TANGE CD-20 1" HEAD SET BALL BEARING RETAINERS 5/32 X 20  BX/10
Common high Japan quality head set retainer for 1" forks in the 1970s and 80s.
Price includes box of 10 retainers
Retainer size is 20 x  5/32" balls.
This retainer measures approximately 36mm across