I purchased this spacer as part of a bundle, (essentially a desktop mobile phone holder, but has many other uses, eg desktop mic stand). The bundle comprises of 4 parts, tripod legs, spacer, universal ball joint and mobile clamp, all of which can be assembled in different ways, step down/up threaded bushes are included. Also, each part can be purchased separately.
This was my first experience of Roadworx products and am very pleased with the choice I made, nothing cheap or flimsy, excellent build quality and solid enough to last a lifetime. One satisfied customer! :)