shaft is but is disposed as a free gear and the first synchronizer mechanism syn 1 is used for connecting the first input gear di 1 with the input shaft is in a case that the first synchronizer mechanism syn 1 is in a neutral state the torque of the input shaft is is not delivered to the first input gear di 1 and the first speed gear do 1 and the reverse speed gear rg do not rotate therefore occurrence of rattle due to rotational inertia may be improved in a case of shifting to the first forward speed however the first synchronizer mechanism syn 1 and the fourth synchronizer mechanism syn 4 are simultaneously operated in a case of shifting to the reverse speed the first synchronizer mechanism syn 1 and the fifth synchronizer mechanism syn 5 are simultaneously operated accordingly at least five shift rails are necessary in a manual transmission according to various embodiments of the present invention referring to fig5 shift rails applied to a manual transmission according to various embodiments of the present invention will be described as shown in fig5 a manual transmission according to various embodiments of the present invention includes a first shift rail 10 a second shift rail 20 a third shift rail 30 a fourth shift rail 40 and a fifth shift rail 50 the first second third fourth and fifth shift rails 10 20 30 40 and 50 are sequentially disposed from one side to the other side shift lugs 12 32 42 and 52 operated by a control finger.