$ dpkg -l | grep linux | grep extra

ii  linux-image-extra-4.13.0-36-generic         4.13.0-36.40~16.04.1                         amd64        Linux kernel extra modules for version 4.13.0 on 64 bit x86 SMP
ii  linux-image-extra-4.13.0-37-generic         4.13.0-37.42~16.04.1                         amd64        Linux kernel extra modules for version 4.13.0 on 64 bit x86 SMP
ii  linux-image-extra-4.13.0-38-generic         4.13.0-38.43~16.04.1                         amd64        Linux kernel extra modules for version 4.13.0 on 64 bit x86 SMP
ii  linux-image-extra-4.13.0-39-generic         4.13.0-39.44~16.04.1                         amd64        Linux kernel extra modules for version 4.13.0 on 64 bit x86 SMP
ii  linux-image-extra-4.13.0-41-generic         4.13.0-41.46~16.04.1                         amd64        Linux kernel extra modules for version 4.13.0 on 64 bit x86 SMP
ii  linux-image-extra-4.13.0-43-generic         4.13.0-43.48~16.04.1                         amd64        Linux kernel extra modules for version 4.13.0 on 64 bit x86 SMP