Used Surplus, Acquired From Spare Parts Storeroom.
This is a tap set to repair M56-5.5 thread. Drill hole out and us the M70-1.5 Tap. Put in the insert.
Comes with 2 M70 taps. 60MM long. 6 inserts. M70-1.5 OD and M56-5.5 ID.
Used but look almost new.