Who told you that Polyphaser's SPD product with screw connections for each lead of Ethernet cable is the only solution in town?
There are many other sources ( Citel, TUPAVCO etc. ) that do not use screw connections, do your homework.
If your Ethernet cable run is between two buildings that have their own grounding systems, the POE (point of entry ) in each building shall have their own primary surge protectors in complience with UL497. Also, when data equipment is significantly away within the building from primary surge protector location is advisable to install as well as a secondary protection device that is in compliance with UL497A or UL497B requirements.
Another case, when the run is within the boundaries of same building - you may use at each point of equipment SPD that is in compliance with UL497A or B only ( use within same shelter and connected to the master ground system ).
