The Spider Holster Plate with Pin for SpiderPro Holster is part of their Single and Dual Holster Systems. The Pin attaches to
the Plate and the Plate attaches to the camera's tripod socket. Once
assembled, the entire rig slides and locks into the Holster. A
two-position locking system secures your camera. When placed in the
lower position, the camera remains firmly in place in the holster. When
placed in the upper position, you can withdraw the camera.