All data necessary to reproduce observed cloud top flight mean effective radius from the PDI, CAS, CIP and PVM cloud probes aboard the CIRPAS Twin Otter during the MASE campaign are contained herein. The script compile_all_reff.m (for Matlab/Octave) can be used to reproduce the data and understand the format of each probe data file; make sure to change file paths accordingly. PDI and PVM effective radius are available from the "<date>_Ps.mat" files as the variables "s_reff" and "s_reff_xg," respectively. CAS+CIP effective radius is reconstructed from time series of binned drop concentration from each instrument (corresponding to file names "Cas_TO_<date>02.dat" and "cip_conc_<date>.csv") and is output as "reff_caps" from compile_all_reff.m. Geometric mean diameter grids for each probe are contained in the files "dp_<inst>.mat" and cloud top leg times are in the file "reff_datestimes.mat" (time in UTC; columns 2 and 3 are leg start and end time, respectively; note: leg times are included for MASE, POST and VOCALS, not just MASE) and the file "reff_proj.mat" identifies the field campaign associated with each entry in "reff_datestimes." POST and VOCALS datasets may be obtained freely from data.eol.ucar.edu to reconstruct all observed effective radii used in Witte et al. "MODIS retrievals of cloud effective radius in marine stratocumulus exhibit no significant bias," submitted to GRL October 2017.