Ukrainische Fallschirmjäger der 77. Separaten Luftmobilbrigade der Luftangriffsstreitkräfte der Ukraine (AAFU) führten von einem Transporthubschrauber aus Übungs-Fallschirmsprünge durch.

that metal box with a lanyard and a cable sticking out is an automated deployment device, when you exit the blue static line pulls the lanyard and starts the pre-set timer (set by the black dial sticking out). when the timer runs out the other end of the cable pulls out of the spring loaded loop and the parachute shoots out.

not sure what the metal thing he is holding in his hand is, it could be a cutaway or reserve deployment handle or even manual main parachute deployment.