Took my tank to be filled at my local diving shop in Feb and haven't used it since. Went to top up my buddy bottle over the weekend and the step down adaptor is missing so can't top my bottle up.

I now need to order a replacement but not sure of the thread sizes. See attached picture...

https://www.flickr.com/photos/jpdbro...posted-public/

What and where can i order one from?

JB