Based on this product's specifications, here are some alternatives and similar models
Avenger Snap In 16mm/16mm-hex aluminium spigot E600 by Avenger
Summary description:
Avenger Snap In spigot E600 is an aluminium 16mm/16mm-hex accessory for mounting and connecting light stands, grip arms and studio hardware. The snap-in design provides quick attachment to compatible stands and fixtures, while the 16mm diameter with 16mm hex interface ensures stable support for lighting modifiers, brackets and clamps in photo and video setups.