Patton Line Protection for Serial
Dial Leased DSL T1 PoE &  Ethernet Extenders

509/25 DB-9 TO DB-9 SURGE SUPPRESSOR RS232
509/6 DB-9 TO DB-9 SURGE SUPPRESSOR RS422 RS485
552-D2 2-WIRE DIAL UP SURGE PROTECTOR
552-D4  4-WIRE LEASED LINE PROTECTOR
552-E1 4-WIRE E1 SURGE PROTECTOR
552-E1   4-WIRE E1 COAX PROTECTOR
552-GS2  2-WIRE G.SHDSL SURGE PROTECTOR
552-GS4  4-WIRE G.SHDSL SURGE PROTECTOR
552-L4  4-WIRE LEASED SURGE PROTECTOR
552-L8  8-WIRE LEASED LINE PROTECTOR
552-ST  ISDN SURGE PROTECTOR
552-T1  4-WIRE T1 PROTECTOR
570  10/100 BASE-TX SURGE PROTECTOR
570-POE  10/100BASE-TX 802.3AF POWER OVER ETHERNET SURGE PROTECTOR
591AF  RS-232 TO RS-232 OPTO ISOLATOR

You can always call for a quick quote.
If you like the price, you can order right over the phone.