The SONAbeam? 155-M is optimized for high-availability links from 300 to 5700 (3.5 miles) meters and supports most standard protocols including OC-3, STM-1, Fast Ethernet and FDDI.

With the sturdiness and stability to overcome the elements, the SONAbeam? M series was designed with carriers' needs in mind. Featuring a rugged, cast-aluminum, environmentally sealed housing and up to 50 times the power of competing products, the SONAbeam? 155-M is the toughest, most powerful system currently available. Quadruple-redundant transmitters combined with a 20cm receiver to further ensure transmission integrity.