These bomb racks may have special store release control mechanisms. Aside from the release options of a rack a pilot can select release mode for releasing one or multiple stores. Stores can be jettisoned selectively in single mode or ripple mode or salvo mode. The term "ripple" applies to the single- or ripple and single- continuous release mode from one or from mirror stations. Salvo release mode applies to a combination of several stations together e.g. adjacent stations. For multiple store release an interval timer can be set to release stores in fixed time steps. For an external store emergency release there may be a "panic button" to release all of the weapons.