slot 62 fracturing fluid injection line 63 is disposed within housing bore 60 and is in fluid communication with frac slot 62 such that fluid flows out of fluid injection line 63 into housing bore 60 and out of frac slot 62 in a vector that is parallel or substantially parallel to the longitudinal axis of downhole tool 40 as used herein u201c substantially parallel u201d means that the vector of the flow of fluid out of fluid injection line 63 into housing bore 60 and out of frac slot 62 is not changed by more than 45 degrees from the longitudinal axis of downhole tool 40 during transition from fluid injection line 63 into housing bore 60 or from housing bore 60 through frac slot 62 in one specific embodiment the flow of fluid out of fluid injection line 63 into housing bore 60 and out of frac slot 62 is not changed by more than 30 degrees from the longitudinal axis of downhole tool 40 during transition from fluid injection line 63 into housing bore 60 or from housing bore 60 through frac slot 62 in another specific embodiment the flow of fluid out of fluid injection line 63 into housing bore 60 and out of frac slot 62 is not changed by more than 15 degrees from the longitudinal axis of downhole tool 40 during transition from fluid injection line 63 into housing bore 60 or from housing bore 60 through frac slot 62 further it is to be understood that the term u201c substantially parallel u201d also includes u201c parallel u201d in which the vector of the flow of fluid during.