Viscosity cup Zahn #2 or Dupont M50

[kcwis]

Are they the same spec?  I have a M50, the Urethane primer calls for a Zahn #2

[zieg85]

Are they the same spec?  I have a M50, the Urethane primer calls for a Zahn #2

Close enough probably but not the same.  There are so many versions of Zahn #2 viscosity cups and they all measure differently unless you get the ultra calibrated $200 ones like I carry for work