P-2 series/Post for lens mount/optical mirror post 

1.Post Holder with spring loaded ball allow one-handed positioning
   Diameter : 8 / 12 / 12.7 / 20 mm

stabil mount

The drawing and the specification:

2.PR4 & PRA4 Series
PR6 & PRA6 Series
PR4 & PR6 Series
PRA4 & PRA6 Series
both of hole are M40.7P(#8x32W)
both of hole are : M6x 1P(1/4x20W)
Material : Stainless Steel
Material : Aluminium (Black anodized)

 Features

1" diameter steel post riser
Stackable
PRB with M6x1P (1/4-20W) clearance hole for most posts and post holders
PR-B with M6x1P (metric) clearance hole for common usage also compatible for
Imperial version 1/4-20W.
PR6-series top and bottom with M6 tapped hole Imperial version is 1/4x20w.
Holding fork with two length for extensive application.

3.P-series : Ø12.7 (0.5")
Features 2 different tapped screw at post top and
bottom
P-series : M4 x 0.7P + M6 x 1P
 

 4.

PF/HFP-series smartEzi-Stainless steel Post