Sekhmet gauge thread is 1/8 bspp ( G 1/8, 1/8 BSP) , which is suitable for most brands of airgun:

Full range of product under brands like

FX

Kalibrgun

Daystate

Edgun

AGT

AirArms

ATAMAN

BROCOCK 

GAMO

HATSAN

TAIPAN

RTI

Steyr Arms

Walther Arms

...

While below brand use other threads like 1/8 NPT which now we don't have same thread:

SKOUT, Air Force, RAW, American Air Arms

& below brand use M8/M10 thread which we also don't have same thread:

M8: AEA,  Air Venturi Avenger， Snow Peak, SEA
M10:LCS Air Arms SK 19