Two Maxtreme products share this substance and the word amp in the name is what separates them. Testo-Enan amp is the ampoule presentation: ten units at 250 mg/ml, each opened once and emptied, with no stopper to re-enter later.
Inside is testosterone enanthate in oil - an androgen carrying a long ester that dissolves out of muscle tissue slowly, which is why enanthate is grouped with the slow-release testosterones rather than with propionate at the short end of the range. The strength matches the figure this ester is conventionally produced at.