This is an extraordinary Zisha clay bamboo style teapot with seal marks of master Gu Jing Zhou on bottom and handle, superior workmanship, from 1960s. It is in excellent condition without damage, except for some tea stains or sediments here and there. It was used before, but recent years it is in display.
FYI, Gu Jing Zhou (1915-1996) is one of the 3 most prominent Zisha masters in history, as famous as Chen Ming Yuan and Shi Da Bing of Ming dynasty.