what's 4d hifu? high intensity focused ultrasound (hifu) directly delivers heat energy to skin and subcutaneous tissue that can stimulate and renew the skin's collagen and thus consequently improving the texture and reducing sagging of the skin. 4d hifu advantage 1,combines traditional 4d hifu handles with vmax hifu 2,one scan be output 12 lines 3,a combination of dual handles. can be treated with 360 degrees without dead ends. 4,each cartridge has 20000 s. low cost 5,screen can display the current number of points in real time. the value of each parameter. 6,can be suspended midway. can continue to use (will not reset).syi