That is a repackaged portion. It does look like the right stuff but it doesn't have the NutraZu product number on it. But I would bet that is exactly what you are looking for.
YES - the NutraZu 50J3 is EXACTLY the same product and formula as the Mazuri 5M21. In fact, it you look up Nutrazu's website and look for the tortoise diet - you get this product discription even still using the 5m21 formula code.
Purina Mills is the parent company and owns the trademarks for Mazuri in N America and Nutrazu in Europe.