It is a quick-release top handle with multiple accessory mounting options.
It features two cold-shoe mounts (one vertical and one horizontal) and allows to mount two cold-shoe accessories at once with a half turn of a lever.
It's also compatible with any Z-Rail. The two cold-shoe mounts have securing quick-release clamps.
This handle offers one 3/8"-16 and two 1/4"-20 screw hole mounts and a 15mm quick-release rod port. The handgrip is hand-tooled from three-quarter maple.