In [11]: ff.units Out[11]: {'1': 1.0, 'Mpc': 3.2398276905128868e-25, 'Mpc/h': 0.6711, 'Mpccm': 3.24077929e-25, 'au': 6.6826242963021147e-14, 'au/h': 138424311218.1805, 'aucm': 6.684587111136851e-14, 'cm': 0.99970636707965599, 'cm/h': 2.0707982245838164e+24, 'cmcm': 1.0, 'km': 9.9970636707965617e-06, 'km/h': 2.0707982245838164e+19, 'kmcm': 1e-05, 'kpc': 3.239827690512887e-22, 'kpc/h': 671.1, 'kpccm': 3.24077929e-22, 'm': 0.0099970636707965611, 'm/h': 2.0707982245838163e+22, 'mcm': 0.01, 'miles': 6.211887366856977e-06, 'miles/h': 1.2867343606282246e+19, 'milescm': 6.21371191723341e-06, 'mpc': 3.2398276905128868e-25, 'mpc/h': 0.6711, 'mpccm': 3.24077929e-25, 'pc': 3.2398276905128867e-19, 'pc/h': 671100.0, 'pccm': 3.2407792899999997e-19, 'rsun': 1.4373923298231678e-11, 'rsun/h': 29774237542602.76, 'rsuncm': 1.4378145194994414e-11, 'unitary': 3.6248111194749401e-27}