A single 15m RCA Coaxial Cable suitable for dolby digital and DTS Audio, Digital coaxial cable for digital audio signals, SPDIF audio is a digital signal used for dolby digital, DTS audio, dolby digital and DTS are audio formats used on DVD / Blu-Ray Discs, so you will find SPDIF (digital coaxial) on DVD / blu-ray players, amplifiers, TV's, computers, Home cinema systems.
Although a digital coaxial cable has an RCA plug it's not the same as a standard RCA cable. Digital coaxial cables are screened RG59 Cables, standard RCA cables although occasionally are screened are not suitable for Digital Coaxial / SPDIF.