Nothing intrinsically odd about this. Fairly clever marketing, in fact--miniature bat-signals! At three for five bucks, you and your friends can be scaring your sisters in the bathroom and flashing coded bat-messages until the D batteries go dead!
What got my attention, however, was the company that no doubt raked in moolah for these unofficial tie-ins! GRAYSON Productions! A wholly owned subsidiary of Wayne Enterprises, perhaps? Looks like the boy wonder decided to exploit the whole bat craze while the exploiting was good! Holy cash-ins, Caped Crusader!