Median CO SLED of the different galaxy types included in SPRITZ: spirals, SBs, Irr, SF-AGN, SB-AGN, and AGN1. The CO SLED of AGN2 is identical to that of AGN1 and is not shown. Different symbols indicate the relations considered to derive the CO luminosity for different J. The dash-dotted cyan lines show the CO SLEDs by Mashian et al. (2015) for J < 14, which are not included in this work, but are shown for consistency. Shaded areas show the one σ variation of the CO SLED for galaxies with 10¹⁰ ≤ L_IR/L_⊙ ≤ 10¹².