TOUGH environment for a cell phone. Had no service at all, as expected, inside an all-aluminum Coastal Cruiser (boat) sheltered under a roof. PLUS, low signal area with 1 bar only at best and sometimes NO SERVICE, even in the parking lot. Have 4 bars now! Gains both set at 50db. Crystal clear both ways and no drops. UNIT does what it claims! Set up took about an hour to run the coax and mount the outside antennae onto an upper railing. Used power strip surge protector at 1000 Joules, as recommended so as to sleep better during storms.