Per 
Item#: SCP-4135
Object class: Euclid
Special Containment Procedures: SCP-4135 is to be kept 5x5x5 meter standard containment cell. The object possesses no immediate threat to personnel who seem to be "in contact" with the object, yet it is advised that personnel should not be in contact for more than 30 minutes at a time, since effects from prolonged exposure is currently unknown. There must always be video surveillance
Description: At first glance, SCP-4135 appears to an old antique mirror. It reflects the hosts image as any mirror should do, but upon touch of the mirror, it is discovered that it's a portal mirrored dimension which has our exact events happen simultaneously to ours.
If a subject were to touch the mirror with their bare hands, they would feel another hand, pressing against their own with the exact amount of pressure they put into their own. No amounts of testing or trying to trick the object have proven successful. The only thing that would ever be able to penetrate the "mirror" is something that is truly random, but even then it is unclear if it would be able to penetrate.
Since the "reflections" in the mirror is not actually considered reflections, they are given the name SCP-4135-1 through x, where x is the amount of people affected by the "Mirror" at the current time.
Addendum 4135-01: ██/██/19██ SCP-4135 is discovered in ██████, France by a group of civilians looking in old mansions in order to see if they would be able to be sold. The mirror was found in the attic by one of the civilians, but they decided to cell it after they find out that the image is "Creepy and weird". The Foundation took interest in the object and bought it off the original discovers. After that it was moved to be kept at Site-██
Addendum 4135-02: Experimentation commenced on the object, multiple objects have been shoved into the SCP-4135, none of which appear to lean into either side of the portal. No matter what was done, no matter how much force we put into something, the equal amount would always be exchanged on the other side, further testing will be done
Addendum 4135-03:
