This device is intended to be used for tensioning chain that doesn't do a full wrap...i.e. in a swerve setup.
It isn't particularly strong, as the 4-40 bolts that are used to attach the chain are meant for light to medium duty loads.
That said it is a very effective and lightweight method for working with this size chain if used properly.
I'm surprised that we don't have a drawing loaded for that product.
I'll get some dimensions later today.