I have no idea how good or bad the cable is; It can work well with other Celestron NexStar models, but definitely not suitable for NexStar 127 SLT. It is intended to be connected via a hand paddle. NexStar 127 has a mini USB port. This cable terminates like a telephone jack in an RJ-11 connector. The Revain rating system asks for my opinion on wire gauge and gauge. Fun.