BE231-664- Reverse valve detent spring 

BE231-AV1-255 Reverse valve detent ball

BE231-665- Set screw

Sold as a kit- (You will receive 4 pcs- Knob.ball. spring and set screw

"  TOOL, REGULATOR, (VALVE) NOT INCLUDED

FOR Ingersoll Rand, Chicago Pneumatic, and several other brands

1/2- impact- 231 all series- 244- Short and long 

Astro

Ingersoll rand

Chicago pneumatic

Sunex

ATD

Mac Tools

Matco

Snap on