SMACO Mini Scuba Tank Valve Accessories series.
M8 8mm scuba tank inflatable valve
If the mini scuba tank was not cleaned in time after diving, it will form crystals in regulator( and cause clogging, the O-rings or other inside the inflatable value is damaged.
There is the replacement parts here.
Again Scott (verified owner) –
The chat with smaco worked flawlessly. Answered my questions and lead me right to my needs. Made ordering easy as can be.