ML3DBOH is the EOS Aura Microwave Limb Sounder (MLS) daily binned on various vertical grids product for hydroxyl (OH) derived from radiances measured by the THz radiometer. The data version is 4.2. Data coverage is continuous from August 2, 2004 to December 12, 2009 when the THz radiometer was placed in standby mode. After this date OH data were collected for about 30 days in August/September of 2011, 2012, 2013 and 2014. Spatial coverage is near-global (-82 to +82 degrees latitude), with a spatial resolution of 4 degrees latitude by 5 degrees longitude. The recommended useful vertical range is from 31.6 to 0.00316 hPa, and the vertical resolution is about 3. Users of the ML3DBOH data product should read chapter 4 and section 3.19 of the EOS MLS Level 2 Version 4 Quality Document for more information.The data files are archived in the netCDF4 format, which is also compatible with HDF5 readers and tools. Each file contains two grid objects (profile and column data), each with a set of data and geolocation fields, grid attributes, and metadata.