A collection of exactly 1000 bits. Not to be confused with kilobyte as this is a collection of 1024 bytes. kilobits and n-bits are often used to quantify serial data communications lines, as they only send bits one bit at a time.

Example:

They have a 128000 kilobit ISDN line which currently has connected a single 64000 kilobit wireless PIAFS user in Japan.