I could not find any reviews comparing the size and tint of the Olight S15 vs. Olight S1A. So.............Both have XM-L2 emitters. The S1A is much smaller than the S15. These are my favorite AA/14500 flashlights. Got the S1A for a super low price at the Olight Store black Friday sale (2017) and a free i3e EOS. As you can see the i3e is much smaller than the Jetbeam.