What is a memory kit?
A Kit is comprised of two pieces of memory. For example..
One 1GB Kit has two 512MB memory modules.
One 2GB Kit has two 1G memory modules.
One 4GB Kit has two 2GB modules.
One 8GB Kit has two 4GB modules.
The only exception to the two piece kit is high end workstation machines by SUN, HP etc. which sometimes have 4 or 6 piece kits.