A disposable measuring tool (100, 200, 300) comprising: a proximal portion (112, 212, 310) having a proximal diameter; a distal portion (122, 222, 320) having a distal diameter; a body portion (132, 232, 330) having a body diameter, wherein the body portion is disposed between the proximal portion and the distal portion, the body diameter is a maximum first diameter in the middle of the disposable measuring tool larger than the proximal diameter and the distal diameter; the body portion (132, 232, 330) is tapered symmetrically from a midline of the body portion (132, 232, 330) such that the diameter and the circumference of the disposable measuring tool decreases toward both the proximal end (110, 210) of the proximal portion (112, 212, 310) and the distal end (120, 220) of the distal portion (122, 222, 320); and a measuring surface disposed on the body portion (132, 232, 330), the measuring surface further including, a proximal marking, the proximal marking being configured to be read uprightly when the proximal end (110, 210) of the disposable measuring tool is inserted into a proximal end of a corpus cavernosum; and a distal marking, the distal marking being configured to be read uprightly when a distal end (120, 220) of the disposable measuring tool is inserted into a distal end of the corpus cavernosum, wherein the proximal marking and the distal marking are arranged in opposite directions, and wherein each of the proximal end (110, 210) and the distal end (120, 220) is made with effectively soft materials to avoid perforations. a proximal portion (112, 212, 310) having a proximal diameter; a distal portion (122, 222, 320) having a distal diameter; a body portion (132, 232, 330) having a body diameter, wherein the body portion is disposed between the proximal portion and the distal portion, the body diameter is a maximum first diameter in the middle of the disposable measuring tool larger than the proximal diameter and the distal diameter; the body portion (132, 232, 330) is tapered symmetrically from a midline of the body portion (132, 232, 330) such that the diameter and the circumference of the disposable measuring tool decreases toward both the proximal end (110, 210) of the proximal portion (112, 212, 310) and the distal end (120, 220) of the distal portion (122, 222, 320); and a measuring surface disposed on the body portion (132, 232, 330), the measuring surface further including, a proximal marking, the proximal marking being configured to be read uprightly when the proximal end (110, 210) of the disposable measuring tool is inserted into a proximal end of a corpus cavernosum; and a distal marking, the distal marking being configured to be read uprightly when a distal end (120, 220) of the disposable measuring tool is inserted into a distal end of the corpus cavernosum, wherein the proximal marking and the distal marking are arranged in opposite directions, and wherein each of the proximal end (110, 210) and the distal end (120, 220) is made with effectively soft materials to avoid perforations. a proximal marking, the proximal marking being configured to be read uprightly when the proximal end (110, 210) of the disposable measuring tool is inserted into a proximal end of a corpus cavernosum; and a distal marking, the distal marking being configured to be read uprightly when a distal end (120, 220) of the disposable measuring tool is inserted into a distal end of the corpus cavernosum, wherein the proximal marking and the distal marking are arranged in opposite directions, and