The Mounting Arm height is adjustable. For the AP700 the bottom of light can be up to 16 inches from the top of the water. For all other Kessil lights the bottom of the light can be up to 13 inches from the top of the water.
The Mountain Arm can be adjusted horizontally. For the AP700 the center of the light can be anywhere from 9.5 to 12 inches into the tank. For the other Kessil Lights it can be from 11 to 13.5 inches into the tank. For wider tanks (front to back) from 25" to 32" (where you want your light at the halfway point of 12.5" to 16") you might also wish to purchase the Kessil Slide Bar-2 Extended Slide Bar for Mounting Arms.
When using the Plastic Steppers (spacers) the tank and tank lip can not be more than 1/2". Without the Plastic Steppers the tank and the tank lip can be up to 1".
You will need at least 3 inches behind the tank for the mounting hardware
Cables can be housed inside the Mounting Arm
The Kessil Mounting Arm can be used to mount the Kessil AP700, Kessil A350/A360 and Kessil A150/A160. For the Kessil AP700 you will need TWO Mounting Arms. For Kessil A350/A360 and Kessil A150/A160 you will only need ONE. NOTE: To use with the A150/A160 you will need to use the bracket that came with the light.