2 off M5 / M6 Stainless Steel Ball Joint ('C' Type - DIN 71802). Condition is New. Dispatched with Royal Mail 2nd Class. 
Part Number BJCM0506SS

Ball Stud has a M5 x 0.8 thread.

Housing has a M6 x 1.0 thread.

The part is a standard M5 'C' Type ball joint with the housing tapped out to a M6 thread.  Suitable for Gas Springs.