This is the old school style of Sanwa Mesh balltops. They are no longer manufacturered.  We were able to get our hands on them when we purchased a large lot of parts from a company that went out of business. When they are gone, they're gone! 

Threading is 6mm and will fit all standard Sanwa and Seimitsu joysticks....and every other 6mm threaded stick out there. The majority of joysticks have 6mm threading.  This will be a great addition to your cabinet or Madcatz or Hori fight stick!!