Photos of my second voltmeter build. I'm using the 12 volt two wire unit which better suits my purpose. Piece layout and assembled views. A small bead of silicone caulk seals the outer edge of the aluminum disk to the plexiglass window. I used a medicine bottle cap with the "child proof" liner removed and notched for wire exit to hold the digital voltmeter against the plexiglass with a slight gap. A wire holds everything in place and additional clear silicone caulk seals the gap and completes a tight, waterproof assembly. Unit is then installed using the original bracket.