Digital Aquatics is teasing us with the new float switch assemblies the company is developing. Prior to this new version, they had your typical, small micro-switch float kits. This new version Digital Aquatics is making is larger and more robust and will most likely we best used in a reservoir or larger where there is more space. According to the information we have, the large nut on the right side of the unit with a rubber grommet to secure and seal it to the mounting hole. The smaller micro-switches are still rather useful for smaller chambers like a protein skimmer cup or as a top off for small all-in-one nano kits. No word on availability or pricing yet. Appreciate the heads up Michael!