Nandrolone PhenylPropionate. Fast acting Nandrolone... Most use Nandrolone Decanoate (Deca).. which is a very long acting ester.
Test Prop and Npp are a fantastic combo, but I would definitely run Test higher than Nandrolone ... I've ran these close together in dose before and I had erectile problems until I remedied it by lowering the Npp and upping the Test.