My Hex Bases were designed to work with Bandai’s Action Base 4 and 5 sets. It’s a single piece of 1/4 inch acrylic with a single peg hole, either in the center or offset in the back. Take the arm from the Action Base set, put it on the Hex Base, and Bob’s your uncle.
What’s great about these is they offer a much cleaner look than Bandai’s offering, come in various colours, but best of all they weigh 3x more (0.6 oz vs 2 oz). This means I can take a Master Grade kit, give it a pose high up on the stand, and not worry about it tipping over. Okay, yeah, still need to keep it centered, but I have MG Wing kits displayed up high and the base is the most stable part of it (looking at you HiRM Wing kits).