Chill. Company is defending its brand name.
1. I cannot call something a Colt, Ford, or EOTech unless that is the brand name.
2. There IS counterfeit merchandise illegally imported into the US. If it MARKED EOTECH but not made by them, they want it off the market. US Customs seizes this stuff by the SHIPLOAD (I was there when they raided the Mile High Flea Market near Denver. They took 3 semis of counterfeit stuff.)
If yours is not marked EOTECH, do not call it that, you should be good. If you get any more from the lawyers, brief note from you, apologize, state yours does not bear EOTECH name, honest error on your part.
IF a company FAILS to defend their brand when it is misused, the brand moves to the public domain, anyone can use it. Cellophane and Band-Aid are 2 that were not defended, and anybody can make a bandage w/ tape and guaze, and sell it as a bandaid (notice the lower case b?) They are trying to defend what they own- the brand name.