about 5 years ago i emailed the illinois DNR about using knocks that emitted a signal that could be tracked with a receiver. i got a reply from Brenda Potts saying that they are not legal in illinois, but the topic would be brought up in some archery forum that monitors rule changes in illinois. after waiting 2 months, the idea was shot down. she said that a number of the members are traditional archers, and that they saw this as something that would encourage careless shots. i could see her point, but most of us are looking for a pass thru shot for maximum blood. i doubt that lighted knock would be legal