This is the "stream rotor on steroids" head that Toro had in their product line for a few years. Radius of coverage to about 40 feet, and capable of standalone coverage from a riser-mounted head, like you could expect from an impact head.
To give the images some scale, the upper right component is a 1/2-inch MPT shrub adapter bottom piece that fits all the other Toro shrub rotors, like the 300, and S700, and S600, just as it was part of the 320 shrub head.
Everything is bigger. Nozzle turret is two inches across, with two opposing distance nozzles and two opposing close-in nozzles. Gear drive is larger and stronger, with a steel output shaft that threaded into a brass acorn nut in the turret. Same kind of stator the 300 series has, with the spring-loaded friction plate that moderates speed.
The arc plates came in a wider variety of arcs than the 300 heads, so there was something a bit more or a bit less than a 180-degree-arc for curved borders. Because having only four nozzles made a quarter-circle head difficult to achieve, the arc discs for those were actually 93 degrees, and so marked. Since these arc discs were so large, the seals for them were O-rings.
Close-in coverage was by way of hole-and-slot nozzle. The angle, down and right of the main spray, worked very well on a riser, because the stream isn't full force until a few degrees into the coverage area, and the right-ward spray fills in what would otherwise be dry, as the streams appear to the right of the head. The left side works like the regular stream rotor coverage, with sprays dropping from full distance to zero, as the turret revolves. It just looks cooler, with the longer water streams in play.
You can see from the construction details that a head like this was doomed no matter how well it covered. It also points out the key flaw in the attempted follow-up head, the XP-300. You needed a wide nozzle turret to have opposing distance nozzles that could really go the distance.
Note that Toro is no longer is connected to the Rain Pro name, since they had to figure it was only hyping the competition.