So my friend did the same thing when, in the case of an intercom or a combination lock, the handles were left on both sides of the door, because they can be useful.
PS
Please pay attention to the arrangement of staircase switches posted by your colleague All In One . How does this system differ from the commonly known system? The correct answer will be rewarded.
PS
Please pay attention to the arrangement of staircase switches posted by your colleague All In One . How does this system differ from the commonly known system? The correct answer will be rewarded.