The present invention provides a framework member by which the amount of impact absorption can be sufficiently ensured. The gear member is axially fixed to the outer member and freely rotatable with respect to the outer member and the gear member threadedly engages a threaded portion of the inner member to translate inner member along the axis. The present invention also provides another process that involves reacting CCl3CF2CF3 and optionally CCl2FCF2CClF2 with H2 in the presence of a hydrogenation catalyst to form CH3CF2CF3 ; dehydrofluorinating; and recovering CH2\u2550CFCF3 or a mixture thereof with CHF\u2550CFCHF2. The knob base includes projections which fit into and mate with channels in knob coupling latching pawls of the knob base; thus, the knob holding force is enhanced, and a clicking sensation confirms completion of the attachment operation. Rotation continues until torque overcomes a resisting force wherein finger disengages from finger aperture, torque ring rotates relative to torque collar, and the amount of closing-direction torque that can be applied is limited.