HW-100 P/N 404-328 2.1 KHz $27. SB-102 P/N 404-284-1 400 Hz $37. Joe Listserver Subscription:listserv at listserv.tempe.gov - "subscribe heath 'name' 'call'" Listserver Submissions: heath at listserv.tempe.gov Listserver Unsubscribe: listserv at listserv.tempe.gov - -"signoff heath"