As shown below: Rear enclosure cover, screwed into the back of the speaker. Please make sure the 4 screws are securely fastened, to ensure the speaker is fully waterproof.
Secondly, there is a male/female receptacle on the rear cover and the speaker, make sure they are aligned, to ensure the speaker is fully waterproof. (If not there shall be a gap water can come in)
There are 3 screws on the metal plate, this ensures the rubber gasket is under pressure correctly to ensure the cables are watertight preventing water through, IMPORTANT the plate applies pressure onto it.
As long as you follow all the instructions above, your IO1 speaker will be kept fully waterproof assuming you have installed the speaker as per the instructions.
Any further questions, please do not hesitate to email support@litheaudio.com