Relay with a test button?

[03mustangdude]

Pool timer stays on and after replacing it with a new timer this is the only thing that hopefully can be wrong. Reading up on it it says it has a test button on the back, click the button and it clicks and goes back to same position. Good test?

[Snatch Napkin]

Looks more like a breaker. A relay will have a different schematic with a "switch" that throws when power is energized.