There is no Link Kas, I got my info from a supplier who imports the heaters directly from Germany. Out of the first 4 cases of heaters he sold all but 2 heaters were returned. The old Ebo Jagers were awesome, however Eheim has ran that good name right into the ground. I can't say if they have infact done some improvements since that time, but it was enough to lose my trust.
Just a side note, the Jagers are all submersible, its just some are sold as UL listed, and UL (underwriters labratories) will not approve them if they are listed as being submersible, however both the ones without UL approval and the ones with UL approval are infact the same exact heater, just one has UL stuck on it. Both "kinds" are submersible.