The R161,39 Crank Handle from Manfrotto raises and lowers the geared center column on select Manfrotto tripods. It is sold here as a spare or replacement part. The handle includes a spring and screw.
Models that include this part:
028B 075B 075 074 058B 058 117B 117MV 117X 161MK2 161MK2B 475B 475 028 074B 028SLE 028B,136 161LC-3B 161LCB