The present disclosure describes an adjustment mechanism for a scope comprising: a first surface and a second surface, the first surface configured to engage the second surface axially when an amount of force is applied to the first surface, the first surface also configured to transfer torque applied to it to the second surface when the first surface and the second surface are engaged, and a member adjustable to apply force to the first surface to engage the first surface and the second surface, the member being adjustable using only one or more human fingers, wherein an adjustment of the member can always be initiated using only one or more human fingers.