Typically 
Gauss for normal pulsars
Consistent with flux conservation during stellar collapse
Typically 
Gauss for millisecond pulsars
Gravity dominates stellar structure
B field dominates exterior
Stellar surface is so small that observed emission is dominated by the
magnetic field.
The electromagnetic wave generated by the misaligned rotating dipole
causes loss of rotational energy and accounts for the observed slowdown
Only field lines inside light cylinder are closed
Particles are constrained move along field lines