The TY178/GRP01 is an 8F 8B Neutral Line Relay for general railway trackside signalling applications where greater current carrying capacity over the back contacts is required, but special characteristics such as AC immunity, slow release etc. are not req Of compact modular plug-in design it has non-weld front contacts and weld-resistant back contacts and is equipped with a safety interlocking system (pin code) for insertion into mating plugboards.