Abstract: The present invention is an improved slip forming device for forming a concrete curb having a desired profile. The device consists of a hopper portion and a removeable extruder portion, the extruder portion being adapted and configured to extrude the concrete curb having the desired profile. The hopper portion of the invention has a top, an open bottom, side walls and a back wall having an opening. The extruder portion of the invention has a front wall, a back wall, a closed top, and open bottom and side walls. The front wall of the extruder has a front opening and the back wall of the extruder has a rear opening, the top and side walls of the extruder forming a channel between the front and rear openings of the extruder. The rear opening of the extruder is substantially in the form of the desired profile. The front wall of the extruder is releasably mounted to the back wall of the hopper such that the front opening of the extruder is in communication with the opening of the hopper.