A strut assembly is provided including a holding and releasing mechanism adapted to be attached to a cylinder-type closer. The mechanism comprises the strut assembly including a strut cylinder, a strut rod, a pivot block, and a locking tube. The strut assembly further comprises a stop tube including a clip at a first end and a collar at a second end. The stop tube further includes a rigid angled ramp connecting the clip and the collar. The clip moves from a first position to a second position while pivoting the locking tube at a first end in order to engage the locking tube at another end with the strut cylinder thereby holding the strut assembly in an extended position.