Averaging kernel in Tropomi netcdf

Hi,
I would like to column average 3D simulations with the same sensitivity/averaging kernel as in S5P. I can get the “DETAILED_RESULTS/column_averaging_kernel” from the NetCDF. I’m looking for the altitudes it corresponds to. I’ve found “INPUT_DATA/altitude_levels” but it has 13 levels and the averaging kernel only 12.
My question: is it the right altitude data to use? Is it representing altitude intervals?
Many thanks,