E-S60VDC: ENVIROMUX DC voltage detector 

monitors up to two DC voltages 

• Monitors up to two DC voltages: -60VDC ~ 0VDC or 0VDC ~ 60VDC
• Connector: Screw Terminal, 5-position
• Supports CAT-5/5e/6 cable up to 1,000 feet (not included)
• Includes mounting hardware