About this item
The Marks USA MESC600A is the entry function lever and escutcheon trim for the Marks X-it M9900 series exit device family. It's the outside trim package that gives the push bar door a keyed lever on the pull side - meaning staff can key in from outside while the exit device handles egress from inside. If you're building out or retrofitting a commercial door with a Marks M9900 rim or vertical rod device and you need controlled outside entry, this is the trim that completes that opening.
What the MESC600A Does and When to Use It
The A suffix in the model number tells you the function. MESC600A is the entry function, which means a key in the outside cylinder retracts the latchbolt when the lever is turned. Without a valid key, the outside lever doesn't operate the latch. Inside, the exit device handles egress normally - the push bar activates and the door opens without any key.
Marks makes two other trims in this series that get confused with this one. The MESC600F is the storeroom function, where the outside lever is always locked and can only be operated by key. The MESC600N is the passage function, where the outside lever is always active with no key required. If you need a keyed entry with lever operation from outside, you're looking for the MESC600A - not the F or N variant.
M9900 Series Only - Not for M8800
The MESC600A is designed specifically for the Marks M9900 X-it Series exit devices, which covers both rim and surface vertical rod configurations. It won't work on the M8800 series, which uses the MESC350 trim family instead. If you're looking at a Marks 8800 series device and trying to find compatible trim, that's a different product line entirely.
Cylinder and Cam Requirement
The MESC600A includes a 1-1/4-inch mortise cylinder with a special cam - the M9907 cam - which is specific to the Marks M9900 trim interface. You can't drop in a standard mortise cylinder with a standard cam and expect it to work. The cam profile on the M9907 is what physically connects the cylinder rotation to the latch mechanism inside the trim. Available in standard Marks C keyway or Schlage C keyway (SC1), so it can be keyed into most common commercial key systems.
If your project uses interchangeable cores, the G3 variant of the MESC600A comes IC prepped with no core and no cylinder, ready to accept your IC cores from your facility's existing key program.
Installation and Handing
The trim uses a thru-bolt design, which means it bolts through the door face for a stronger and more rattle-free connection than surface-mounted alternatives. It's non-handed from the factory and field reversible, so there's no need to specify left or right hand when ordering. Standard door thickness is 1-3/4 inches for wood or metal doors. For the M9900 template and installation instructions, Marks USA's documentation covers the full door prep requirements for both rim and vertical rod configurations.
Specifications
Model: Marks USA MESC600A
Function: Entry (keyed outside lever, exit device inside)
Compatible Exit Device: Marks X-it M9900 Series (rim and vertical rod)
Grade: ANSI Grade 1
Design: Thru-bolt, non-handed, field reversible
Cylinder: 1-1/4" mortise with M9907 special cam (included standard)
Keyway Options: Standard Marks C keyway or Schlage C (SC1)
IC Prep Option: G3 variant (no core, no cylinder)
Door Thickness: Standard 1-3/4"
Door Material: Wood or metal
Finishes: 26D Satin Chrome, 10B Dark Bronze
American Locksets has stocked Marks USA exit device trims and the M9900 series since 2001.
Trusted Since 2001
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