Hi, I am looking for a ultrasonic sensor/actuator couple which is in the position to transfer signals in air about 100 m. Does anybody knows a supplier for such devices. With kind regards Dirk Zielke Dirk Zielke GEMAC mbH Matthesstrasse 53 09113 Chemnitz Germany Tel.: +49 371 3377 131 Fax.: +49 371 3377 272 email: gemac.chemnitz@t-online.de http://gemac.c.ntg.de (Deutsch) http://gemac.c.ntg.de/mst_eng.htm (English)