OWL LH-1310 Laser HOOTS Singlemode Optical Talk Set Light Source 1310nm is a set of 2 optical talk sets that offer secure communication that is unaffected by electromagnetic interference. OWL LH-1310 Laser HOOTS Singlemode Optical Talk Set Light Source 1310nm also doubles as a -10dBm singlemode light source and features long battery life and a signal strength indicator.