Voltage Stabilizer Kit

[zo6om]

hi

can i use two VOLTAGE STABILIZER KIT in same time for one car

i mean i need 2 connect two VOLTAGE STABILIZER KIT in same car battery

http://us.st11.yimg.com/us.st.yimg.com/I/yhst-82176263127385_1920_15208249

any problem becuase i have 2 different VOLTAGE STABILIZER KIT one with digital display for reading and other with LED power on/off????