 Why is Rolf's weapon so valuable in the fights with the Furry?
Sisko Rolf's stocky body was a blur of motion as he cut the rocket jets, doused the twin searchlights, and switched over to the audio beams that served so well on the surface when blind flying was in order. "Trapped us neatly," Rolf said through clenched teeth. Rolf swung the lax controls over hard as the bursts of fire revealed a looming barrier of stone dead ahead, and then he felt the tough skin of the flyer crumple inward. Somehow Rolf found the strength to wrap his fingers around the control levers and snap on a quick burst from the landing rockets. The ship struck; split open like a rotten squash, and Rolf felt himself being flung far outward through thick blackness. The young patrolman unzippered his jacket pocket and felt for the emergency concentrate bars that were standard equipment. Half of the oval bar he crushed between his teeth, and when the concentrated energy flooded into his muscles he set off around the irregular wall of the pit. "They may have found the sunken seas of Mars," thought Rolf as he moved alertly forward, "water that would give the mining domes new life." As the spinner dropped him slowly down into the vast emptiness of the great shining gulf, Rolf could see that a broad band of stone divided the green fertile plains and forests from the desolate desert wastes of the other half. Toward this barrier the spinner bore him, and Rolf was content to let it move in that direction—from the heights of the wall he could scout out the country beyond. The spinner had slowed its speed; it seemed to Rolf that he must be falling free in space for a time, but the feeble gravity of the tiny world tugged at him more strongly as he neared the wall. Deftly Rolf nested the spinners again in their pack before he set out toward the heaped-up mass of stone blocks that was the wall. Ten steps he took before an excited voice called out shrilly from the rocks ahead. Rolf's slitted gray eyes narrowed yet more and his hand dropped to the compact expoder machine-gun holstered at his hip. "You know their leader, Cannon, wanted you. "Sorry," said the tall man as Rolf sprang easily from the ground to their side. Rolf's voice was low, but he saw Altha's lip twitch. A hundred paces away Rolf made the dark shapes of armed warriors as they filed downward from the Barrier into the blackened desolation of the desert half of Lomihi. "They cross the Barrier from the fertile plains of Nyd to raid the Hairy People.
 It's much more technologically advanced than theirs.
 The Hairy people need all the extra weaponry against the Furry.  He's able to catch the Furry off guard with his expoder.  It's much more technologically advanced than theirs.  He's a skilled marksman and able to hit many targets at once.