From Kotobukiya:

The missile can be removed from the pylons, giving the pylon’s base the ability to be opened and set level on a surface.

[Model Specifications]:

The 4 missiles attached to the pylon can all be removed. The base of the pylon is moveable to be opened and set level.
The Missile and Rocket Pod both use 3mm joints which are compatible with the Frame Arms, Frame Arms Girl, Megami Device, and Hexa Gear series.
The connection joints on the rocket pod can be removed. Two types of connection joints and mount parts are included.
There are one A-type 3mm connection joint and three B-type 3mm connection joints included.

[Included Items]:

Missiles x1 set
Rocket Pod A-Type x1 set
Rocket Pod B-Type x1 set
Note: Includes missile and rocket pod parts only. Frame Arms and other kits sold separately.