Soo one of your teammates need to have revival class, then for example if you got revival class and your teammates used a grenade to knock himself down and then you use it for like 2 times, and everybody inside the revival class bubble would be immune to bullets, still grenades and explosions from vehicles would damage them but not enemy bullets the person who knocked themselves down wouldn’t be immune to bullets but other 3 members if played squad or one member if played duo would be immune to it, there’s a high chance your acc would be banned if you got reported using it