A cartridge unit for use with a urinal is disclosed that does not need water to work nor does it use a body of oily liquid sealant as an odor barrier. The odor trap cartridge unit used in this urinal has a spring locking mechanism that works as a valve. It is opened by liquid weight when the urinal is used and lets urine or any other liquid pass downwardly through it and prevents odors from flowing back up towards the room. The cartridge unit has a few disks, two main cylindrical devices, a spring, a fastener, an o-ring, and a coupling; these all operate to open and close a spring sealed trap. These are all placed within a unique three-sized shell that supports the entire cartridge and is fitted into a urinal opening. An umbrella shaped part completes the cartridge by protecting its components from violent fluid flow.