The Xindi-Insectoid rifle was a rifle type of weapon used by the Xindi-Insectoids in the 2150s. It could emit a blue pulse of unknown energy with enough force to kill a Human and knock them back several meters. (ENT: "Rajiin")
In the final draft script of "Rajiin", the Xindi-Insectoid rifle was described as "bizarre-looking". The fact it was to be a rifle was not disclosed in the script, where it was simply referred to as a "strange-looking weapon". Its output was described as "a rippling distortion wave [...] like concentric circles on a pond, but pulsing through the air".