Pressure Grip was a popular lightsaber accessory. The pressure grip would sense when the wielder was no longer holding the lightsaber and immediately deactivate the blade.
Many Jedi incorporated the pressure grip into their lightsaber construction, as can be seen in the following instances. Qui-Gon Jinn dropped his lightsaber when he was impaled by Darth Maul, which deactivated. Anakin Skywalker was disarmed when he was riding on top of Zam Wesell's air speeder on Coruscant. His lightsaber deactivated and then was caught by Obi-Wan Kenobi. Obi-Wan Kenobi dropped his lightsaber when he was fighting General Grievous on Utapau, which deactivated and fell to the ground. It was found and returned to him by Clone Trooper Commander Cody. General Grievous's lightsabers likewise deactivated when he was disarmed by Obi-Wan Kenobi.
- Jedi Academy Training Manual