Check the UseHDR option, and there are two more RenderTextures in runtime memory

Hi, I am using Unity to develop games for Android platform. When I checked UseHDR in Tier Setting of GraphicsSetting for Android platform and built the Android package, When I was running the game on an Android phone and looking at the memory usage with the MemoryProfiler, I noticed that there were two more Rendertextures in memory. Why are there two more Rendertextures and what are their roles?
Any answer will be helpful to me, thank you!