LD200 Hewland transaxle dog ring.
Original 8-Dog design. A Standard 4-speed Hewland LD200 will use x2 dog rings in total, one for each hub assembly (1st/2nd and 3rd/4th).
Dog rings are commonly considered a wearing item in a Formula Ford gearbox, so keeping a couple of these in your spares inventory is always a wise move.
Rate of wear depends on driver, engine power level and transaxle oil used.