The pararang’s body is wrought from an alloy of aluminum and neutronium, the latter of which grants it the strange gravity of a dying star. From the perspective of the person who attempts to throw it, it presses back against their palm with equal force, and never actually leaves their grip. This serves as an indication that it is working as expected.
Its curvature is similar to that of a typical returning boomerang, except for the Möbius-like twist at its center, which bisects it into two wings of equivalent length. Because of this, both sides of the boomerang serve as both its top and bottom, and inlaid diodes along its edges help to distinguish which is which; one half is made to glow red, the other, blue. This binary contrast ensures that the wielder doesn’t mistakenly throw the pararang in the opposite direction to that which they intend.
This is because, though its trajectory is imperceptible to human senses, the pararang does indeed leave the hand of the one who throws it. Rather than being bound to three-dimensional space, its strange wings allow it to glide forward or backward through time as well, then return to the point in the present from which it came. If the blue side is oriented upward in the throwing hand, it will spin clockwise, and flutter forward into the future; if the opposite is on top, however, it will launch counterclockwise into the past. Its typical range is several hours in either direction, though a particularly strong and experienced athlete is capable of tossing a pararang several days forward or backward.
One might expect, given the nature of the pararang, that were it to strike or change anything during the course of a pastward journey, it would then simply disappear from the hand and never find its way back- or, in the case of a particularly severe mistake, prevent itself from ever being thrown. Despite these being the intuitive results, such things have never actually been observed. Time is a resilient animal, and it has no reason to obey human expectations of “if” and “then;” all matter bends to preserve its integrity. Indeed, the pararang never leaves the hand that throws it, but upon its return, there's no telling who will catch it.