Disclosed are compounds, compositions and methods for treating diseases, syndromes, conditions and disorders that are affected by the inhibition of MGL, including pain. The single axle transmission provides a simple manual shifting method for the user. And at least one pair of opposed vertical groves 22 formed on inside of the left and right side walls 4a, 4b and a movable wall 21 engaging with the vertical groves 22 to separate the space above the inclined face 9 of the bottom plate 6 into a front space and rear space.