Hub Heat treatment
ETFACE:High Frequency Heat Treatment to ensure the surface hardness，to have long-life working
OTHER:No heat treatment。No long-life working
The thickness of the facing
ETFACE:Reach 3.85mm to have more using time
OTHER:less than 3.5mm
Confortable driving
ETFACE:With the damper springs, middle size damper springs and pre-damper springs. Ensure the confortable driving
OTHER:Just have the damper springs, no middle-size damper springs, no pre-damper springs.No confortable driving
Cushion segment
ETFACE:
1. with the cushion segment same as SACHS
2. with the wave on the cushion segment same as SACHS
3. material: 65M
Make sure feel soft and comfortable when change the shift during the driving
OTHER:
No cushion segment or no wave on the cushion segment
Feel uncomfortable when change the shift
