Mark FS01 Bedienungsanleitung Seite 11

(2)Install 4*AA batteries, follow the 'UP' directions
inside the battery compartment to correctly
replace the cover and secure the screws.
(3)If you want to put the sensor outdoors,
remember put the accessories waterproof
silicone screw cap on the four screws.
3.SOUND VOLUME CONTROL:
Press the volume button on the receiver to
choose the right volume through 5 volume levels.
Waterproof Silicone
Screw Cap
10