UK Oftel NS/G/1235/W/100025. Quad 0.75A twisted-pair lightning surge arrestors. "4 pair enhanced surge protector suitable for twisted pair signalling applications Very low let-through voltage between all lines Very low (1 ) in-line resistance Space efficient Sturdy, flame retardant, ABS housing Built in DIN foot for top hat and G DIN connection for easy installation. Product can also be flat-mounted Colour-coded terminals which can be removed for easy installation Earthed via DIN rail or M5 stud"