This is a standard radio relay tower with a view of Summersville Lake far to the north. The building is surrounded by a combination of wire fence and wall and there is an old Jeep parked on the road outside. Laser turrets guard the building entrances to the southeast and southwest.
Inside the building is a gray system relay terminal which US government supply requisition holotapes can be loaded into. There are fold-down cots and lockers along the northeast wall and both an ammo box and first aid box beside the lockers. Various chems may also be found scattered around the building, but not much else of note.
Random modification - Under one of the cots along the northeast wall.
Relay tower DP-B5-21 appears only in Fallout 76.