Quality product, very good seller, answers quickly to questions.
The documentation for non Chinese is lacking but Rtelligent support was able to help me out. The support was very responsive and helpful. The product looks skookum and had fast delivery. I used 5V signals for the input terminals. For 5V you have open the driver and place jumpers on the PINS (J2 PUL J3 DIR J4 EN) There is a tuning software for stepper driver but it works well out of the box without tuning. You can download the software and USB driver on szruitech support section. I'ts in Chinese so I used my phone to translate it. The program is in non unicode Chinese, you might have to change region settings in windows to Chinese. For now I don't need to use the software, might come in handy for the future, hopefully there will be an English version ;) I'm very pleased with my product, looking forward for future business.