sustanon is a test blend, made with short, moderate and long esters. the numbers you're reading are referring to the combined amount of MG in each ML. pharm brands of sust are made at 250mg/ml. GP has slightly upped the mg per ML in their version so you're getting 20 more mg per ml. 20mg on it's own, is a very mild difference compared to the several hundred mg's you are already going to be run. over several shots though, it will push up the amount of mg's you're getting per wk.