PCB mount right angle legs with "snap in" support legs on the side.
1/4" (6.35mm) round shaft.
Could be a mix of Cusack, Alpha, Mammoth, or Vimex. Equivalent to Alpha RD901F-40-15R1-value
Specs of Cusack 9mm pots
Tolerance: <10% typical, 20% max
Insulation resistance 100MΩ min at 250vDC
Power: .05w B taper, .025w A/C/W
Rotation life: 10,000 cycles minimum
Rotation angle: 300° (+/- 10°)