This HC-SR04 has stable performance and high ranging accuracy. Compared to the Shap IR ranging module , HC-SR04 is more inexpensive than it . But it has the same ranging accuracy and longer ranging distance.
This product has stable performance and suitable for long distance measurement. I use it to construct intelligent robot obstacle avoidance function of the project. Work as expected. I plan to purchase more for my other projects. (Posted on 5/8/2017)