Full size acoustic w/ electric option. Controls have “Martin & Co.” logo that lights up green (back lit) when red power button is turned on. Takes 9V battery in bottom insert of guitar. Cutaway body, 6 string, 3 + 3 chrome tuners. Wish there was more information on my guitar. Even professional luthiers say this DM-4C just sounds great. Says made in Korea inside. Serial number stamped into frame, along with DM-4C. Bought used in 1997-1998. Sigma est. 1970 on top of neck.