to shackle groups of large spirits
The Spirit Shackles were a device invented by Tracy the Gorilla to handcuff several ghosts at the same time.
The Ghostbusters travelled to Stone Henge to look for a fragment of the tablet which held the whereabouts of Jake and Eddie's fathers. Sir Trancelot used his trusty Trance Lance to zap the rock formation and make it come alive.
Jake told Tracy to use the Spirit Shackles, which the great gorilla grabbed from his backpack, adjusted by hand and threw up in the air. Once airborne, the shackles extended even further and reached out to grab the arms portruding from the Stone Henge stones, binding them from doing further harm and countering the Trance Lance spell so that the rock formation returned to normal.
It was as if the shackles had been made especially for a situation such as this.