Expand Lifebuoy / Lifebuoy

When lifeguards or common people find someone drowning at the bank, they throw out the lifebuoy first so that the drowning people can catch the floating object without sinking. If the lifebuoy is not thrown precisely around the drowning people and the drowning people have no strength to get close to the lifebuoy, it does not work at all.
Expand Lifebuoy can expand the rescue scope. After the lifeguards throw it out, the four handles around the lifebuoy get expanded because of the rotate tension. The expanded handles can increase the number of rescued people and enlarge the rescue scope for more than one time.