Works perfrectly, new lease of life for my quadraverb

I bought a vintage Alesis QS6, which needed a power supply. After quick search online Amazon results popped up with the cheapest option. Weirdly this same power supply has been listed as Power Supply Replacement for Alesis QS6 Adapter Ac 9V 2000Ma, but at much higher price. I compared the images and they were identical with the same make/model details. I order this one to save a few quid and it's the same as in photos of the both product pages. I don't know what's the deal here, but this one worked just fine with my QS6.

Judging by the size and weight of it (it's fairly weighty), this is a transformer based PSU and not a switch-mode PSU. That said, it does the job.