Matthews 6" Pin with Collar

The 6" pin w/ collar is a 5/8" pin which will fit in the A2033F Kit.

The Matthews Pin with Collar - 6" does fit into the bottom of the Glidecam Devin Graham Signature Series Docking Bracket. And the pin will work with a grip head on a c stand arm.

The hole is used to add a split pin, a metal fastener in order to safety the mounted equipment.

The smooth end is grabbed by the grip head with the thicker collar butted right up against the grip head plates. The majority of the pin should be sticking out of the grip head with the knurled undercut(bumpy part) furthest away from the grip head. This is the part of the pin you will attach the light or modifier to.

It's a standard 5⁄8-inch Baby pin. The Aputure, like most professional lighting for still photography, has a 5⁄8-inch receiver. So yes, this will fit. This will work with just about any pro still photo lighting gear. The exception would be equipment that only has a threaded tripod mount and no other receiver. And even those can sometimes work, with the appropriate adaptor. The other gotcha is professional motion picture lighting, which could potentially take the larger Junior fittings.

All of the 5/8" Baby pins have the Anti-Twist Knurling.

This is a standard 5/8" pin that will in interface with all baby receivers such as the one used by Profoto.

No, the base is solid.