The German S-mine (Schrapnellmine, Springmine or Splittermine in German), also known as the "Bouncing Betty" on the Western Front and "frog-mine" on the Eastern Front, is the best-known version of a class of mines known as bounding mines. When triggered, these mines are launched into the air and then detonated at about 1 meter (3 ft) from the ground. The explosion projects a lethal spray of shrapnel in all directions