Kamiquasi on COM-10791 - Right Angle Tactile Button

That depends on what you mean by on/off button :)
This is a momentary button.. so you push it to make contact, and when you let go, it breaks contact. Almost all buttons at this size tend to be.
If you wanted one that you push to turn something on, then it remains on when you let go, and push it again to turn something off, you end up with something like Stomp Switch – DPDT, or another type of switch entirely.
Note that if you’re using a microcontroller / arduino / whathaveyou, you can pretty easily turn a momentary button into a non-momentary one in the code you’d write; as long as it wouldn’t be used as a power switch to the microcontroller itself ( that would require further shenanigans :) )