VMware ESXi 5.1 Update 1 Recovery Image

Why is there no VMware section in this forum?

My question is about the VMware ESXi 5.1 Update 1 Recovery Image. I planned to use this for new installs on Dell blades feeling it would include the latest drivers for my Dell M620 and M820s and would preferrable to the base VMware image

The description says "This ISO image should be used only to recover/reinstall VMware ESXi image to SD Card/USB Key on Dell Supported Platforms."

I'm confused by the mention of SD Card and USB Key to the exclusion of standard hard drives. Is this not the image I should be using for new installs to hard drives?