Please check to see if the Skimmer Box you are ordering matches the Skimmer you have currently. All 3 Sizes are different and need to be correctly matched with your skimmer to function properly.
Tunze Skimmer Box: 6 1/2" X 4 1/2" X 10 1/4"
Octo 110 INT Skimmer Box : 11" X 8 5/16" X 10 1/4"
Qcto 115 INT Skimmer Box: 12 3/4" " X 8 13/16" X 10"
