MIL-PRF-32150A, PERFORMANCE SPECIFICATION: STATIC AUTOMATIC BUS TRANSFER SWITCH (SABT) ON SURFACE AND SUBMARINE NAVAL VESSELS (07 JUN 2007)., This specification covers the Static Automatic Bus Transfer Switch (SABT), herein referred to as the SABT (see 6.4.23) or the unit, for use on surface and submarine naval vessels. Requirements for Automatic Bus Transfer Switches (ABTs) and Manual Bus Transfer Switches (MBTs) are not covered in this specification. MIL-PRF-17773 specifies the requirements for ABTs and MBTs.