The equipment was officially designated Electro Magnetic Frequency Scanner/Jammer. Predictably SpecFor agents short it to EF Sticks. Then they were ef-sticks. Then F--- Sticks with good reason.
The EMFS/J was a small compact and hellaciously powerful radio frequency scanner. It could pinpoint transmissions and jam them. Power was provided by a customized solium fuel cell and later paired conductite superconductor rings. The 'stick' had a protective cover that was closed when not in use. Pushing the button on the side opened the cover and extended a small antenna. Pressing the square red button under the cover initiated jamming. Up to four signals could be jammed at once.
The incredibly compact power source was a problem. If damaged badly sticks could explode with the force of several sticks of dynamite. Ruggedized construction made that unlikely for any damage that would leave the operator alive (those are really tough covers.)
SpecFor agents used them to disrupt communications of ground forces to delay response or confuse pursuit. In many cases they would have to leave the stick behind as it would draw fire. Eventually someone realized the power sources had another function and wired their stick to explode if tampered with. The new practice was to turn the jammer on, rig it to explode and leave it for the enemy to find. They had the choice of leaving it on or disarming it and risking an explosion (which they were unaware of the first few times they encountered the sticks).
Eventually the Brass got wind of this highly unorthodox and effective procedure, issued orders to the engineers and the explosive feature was upgraded fro flaw to design feature. The new explosive mode was activated by hitting both red buttons then giving the handle a half twist. The manual recommended leaving at a brisk pace. Most SpecFor agents opted to run like hell.
The aggressor forces grew tired of being blown up while doing their job and their new protocol was to disintegrate sticks when they encountered them. The sticks were small targets and an off center hit was likely to flip it around and set it off. In addition disintegrators were short ranged and increasing the explosion radius beyond the disintegrator radius was doable. Some agents opted for slipping a non-metallic fragmentation cover over a stick before dropping it to increase lethality. SpecFor agents are notorious for dirty tricks in the field.
A number of copies and knock-offs have found their way into the black market. The explosive trait may be more of a flaw in these than a design feature. The 'civilian' models also may have a flaw when're counter jamming can activate the explosive mode.
(thanks to Luke Campbell for superconductor warheads in his Vergeworld series, Raymond McVay for development,and Winchell Chung for ubiquitous posts and help developing this shiny)