There are two basic units.  Each opens up by pressing in the face and releasing.  The wipes are then accessible. The in-wall unit fits nicely in a standard wall and can be mounted by cutting a hole in the wall (typical residential installation).  The other unit can be mounted on the surface of the wall (for restroom stall partitions) and all wipe manufacturers refill packs fit in the dispenser. 

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Click HERE to see typical installation