This 6mm size is a larger size normally either used for gas or long draw keg systems.  It does not apply much flow resistance so is generally not used in kegerator systems.

If you did use this beer line in your kegerator you will need about 6-8meters of beer line to get adequate flow resistance.  Preferably use the smaller 5mm or 4mm ID lines for Kegerator setups.

This type of line is quite commonly used with the ice bank systems or temprite systems.  It's a very common size for long draw keg systems where lower line resistance is desirable.

Pressure Rating (with 1.5safety factor)
30C - 1.4 MPa (200psi)
50C - 0.7MPa (100psi)