32x32mm

use one 32x32mm sticker for EMF protection on non-smartphone. for smartphone, use two 32x32mm stickers of any design, or one 44×44 mm sticker. for iPhones (the 5 & 6 series & anything introduced after iPhone 6) please use three 32x32mm or one 44x44mm plus one 32x32mm stickers

More detail: http://divinefrequencies.com/CH_home.html