In a standard installation with 7000 or Wireless Master Clock transmitter:
Pyramid 5300 acts as a power booster by adding a fresh supply of 24VDC out to buzzers and bells.
Connected by BCD cable back to the wireless transmitter, or anywhere on the daisy chain with the 7000 (or directly to it), it keeps the bells synchronized with the master clock.
Just add-it-in as needed for more 24VDC bell power.