What precautions should I take when installing the depth sounder?

Disconnect the battery during installation and use insulated wire terminals, preferably ring type, on all connections to the power source. When securing the instrument, tighten the back-clamp nuts to only six inch-pounds of torque — only slightly more than finger-tight — as over-tightening could damage the instrument and may void the warranty. Cut a 2-1/16" diameter hole in the dash for mounting. (Page 2)