RadioShack 25-Foot Shielded Microphone Extension Cable 25-foot shielded microphone cable extension has a 1/4" plug on one end and a 1/4" jack on the other Shielded to preserve signal strength and guard against hum Take your performance to new lengths. This 25-foot shielded microphone cable extension takes you to new lengths. It features a 1/4" plug on one end and a 1/4" jack on the other. Shielded to preserve signal strength and guard against hum.