The board consists mainly of two 47uF capacitors and a 35A N-channel MOSFET, which, according to printing and bore yet another (fear) capacitor can be placed between 12V and ground. The circuit as a whole perfectly okay, because a MOSFET has been used instead of a relay, there are also no "click" sound. Whether this is positive or negative, one may decide for themselves.
If you want to use the flasher relay in a humid environment, it is advisable to seal the soil at the edges toward the housing, albeit with a hot glue gun.
