From The Stargate Omnipedia
Aris Boch's forcefield trap
A shield used by Aris Boch
for the purpose of trapping bounties. Unlike the personal defense shields the Goa'uld
equip themselves with, Boch's shield will not allow a slower-moving object (a thrown knife as opposed to a bullet) pass through. The shield is sensitive enough to stop any object from escaping at any speed.
In this respect, Boch's shield is far more similar to Tok'ra force shield technology. It may also allow objects to move inside the field, though this is unproven.
Deadman Switch - Aris uses a forcefield trap to capture SG-1.