It has three inner diameter series, which are respectively suitable for the corresponding support rods；The special inner wall structure makes the support rod have a high stability contact of 1 point and 2 lines；The inner wall structure is also conducive to ventilation, convenient to remove or put in the support rod.
| Φ12.7 series support rod frame bottom is 1/4-20UNC external thread, suitable for the imperial thread series optical base； |
| The bottom of the Φ12 and Φ20 series support rods is M16X1 external thread, which is used to install the rod base. |
