linux-headers-5.10.0-43-common-rt - 5.10.251-5 main

This package provides the common kernel header files for Linux kernel
version 5.10.0-43 with the PREEMPT_RT featureset, generally used for
building out-of-tree kernel modules. To obtain a complete set of headers
you also need to install the linux-headers-5.10.0-43-(flavour) package,
matching the flavour of the kernel you intend the build for.