I3 Pro vs I3 Pro B

[abulafi]

What is the difference between Acrylic Geeetech I3 pro and Acrylic Geeetech I3 pro B?
I cannot tell any from the pictures?

http://www.geeetech.com/acrylic-geeetec ... p-884.html
http://www.geeetech.com/acrylic-geeetec ... p-917.html

How can the I3 Pro B print in 5 materials while the Extruder is the same on both?

[abulafi]

Would someone please answer the question.

[zhangxueyou]

The tube in hotend is different.
Firmware is optimized.