Which Bashsea sump do you have?I had to do some minor modifications to my Bashsea sump's top plate by reaming out the acrylic by 1/8th inch, and now it fits perfectly. I am glad to be using the FLIR DI-7. I suggest you install a Acrylic plate with the proper round hole (cut by TAP Plastics) so you can use that awesome Trigger. If the narrow part of the oval needs to be expanded, a Dremel does the trick.