This is an extremely famous testosterone blend among bodybuilders, but is perhaps best known under the brand name Sustanon. In fact, there is absolutely no difference between Sustanon 250 and Supra-Testosterone except for their name, the brand that produces it and the price, whereas Supra-Testosterone is much cheaper but of the same quality.
It is an injectable combination drug of 4 different testosterone esters which are all anabolic androgenic steroids (AAS). This product contains: propionate, phenylpropionate and disocaproate and also testosterone decanoate. They all offer the exact same hormone testosterone, so why mix them? Each ester has a different release time when administered.
That being said, each form of testosterone is released into the body at different times. By using a combination of 4 you receive testosterone very quickly thanks to the fast acting testosterone esters, but at the same time you have a sustained release thanks to the long acting esters.