The DIN retaining knob tool is used to get the DIN retaining knob o-ring over the sharp threads without damaging them.
By using this tool the job is done quickly and the O-ring is still in perfect condition.
Place the tool over the threats of the DIN retainer knob and slide the O-ring in its place.
 
The DIN retaining knob o-ring installation bullet for Scubapro first stage is precision machined from white acetal.
 
GTIN: 8720828266380