Dial (Resident Evil Zero)

It looks like an ordinary dial similar to those found of safes...

Image of Dial
A dial used to open a combination lock.

Use this on the locked white door in the Elevator Passage of the Laboratory B2. You then need to enter the pass code using the dial as the input mechanism, which based on reading the file Leech Growth Records is "4863". Once entered the door will unlock allowing you to access the Machine Room 1F.