A pressure based explosion, for example, a bomb, in a conseal area (the shell) as pressure builds up during the detonation, pressure builds up enough to amplify the explosion power of the bomb, giving the explosion more speed and destruction power. Another example, a pipe, too much water in the pipe and no space in between, pressure builds up, and steam bursts out from the pipe in a some what powerful explosion. But depending on the amount of pressure would be the amplification on the explosion
DESL is pressure sensitive, as are C-4 and NITR. That would work for bombs, as you mentioned.