Genuine Monroe X Series Supply
Monroe M33X Black/Red Printing Calculator Ribbon Cartridges
Keep your Monroe X Series printing calculator ready for two-color audit-tape printing with the M33X black/red ribbon cartridge. The cartridge design reduces direct ribbon handling during replacement and fits every current Monroe X Series printing calculator.
Compatibility notice: M33X cartridges fit current Monroe X Series models only. They do not fit earlier non-X models such as the Classic, Ultimate, 8130 or 8145.
Choose the Quantity That Fits Your Workload
Single
One replacement cartridge
6-Pack
Office-ready supply
12-Pack
Bulk workplace supply
Two-Color Printing Without Threading Spools
The M33X places the black/red fabric ribbon inside a drop-in cartridge, reducing the handling required when replacing a traditional twin-spool ribbon. Once positioned correctly, the cartridge supplies both colors used by compatible Monroe printing calculators.
Monroe's True Red™ ink provides a distinct red output alongside black figures for clear two-color calculation records.
Product Highlights
- Black and red output: Supports the two-color printing system used by Monroe X Series calculators.
- Cartridge installation: Reduces direct contact with the inked ribbon and eliminates manual threading between separate spools.
- One ribbon across the X Series: Works with all seven current Monroe printing calculator models.
- Multiple purchasing options: Available as a single cartridge, 6-pack or 12-pack.
- Made for calculation records: Designed for offices that rely on printed audit tapes, receipts, totals and calculation documentation.
- Replacement guidance: Monroe recommends changing the M33X after approximately two paper rolls when maximum print contrast is important; actual life varies with printing volume and operating conditions.
Compatible Monroe X Series Calculators
Select your model below to view the current calculator listing.
Not sure which ribbon your calculator uses? Open the Monroe Ribbon Compatibility Chart.
Keep Replacement Ribbons Within Reach
A single cartridge is practical for an individual calculator, while 6- and 12-pack options help accounting departments, banks, retailers, schools, government offices and other multi-calculator workplaces maintain replacement inventory.
Store unopened ribbons in a cool, dry location away from direct heat and sunlight. Keep the cartridge sealed until it is needed to help protect the ribbon during storage.
M33X Installation and Removal Videos
How to Install the M33X
How to Remove the M33X
M33X vs. Previous-Generation P51S Cartridges
The M33X is designed for current Monroe X Series calculators. The P51S is intended for select earlier Monroe models and is not interchangeable with the M33X.
View Monroe P51S RibbonsCompatible Paper and Ribbon Alternatives
Calculator Paper Rolls
Shop 2 1/4-inch calculator paper rolls for Monroe printing calculators.
View Calculator PaperP65M Twin-Spool Ribbons
Current Monroe X Series calculators also accept P65M black/red twin-spool ribbons.
View P65M Ribbon SpoolsFrequently Asked Questions
Which calculators use the M33X?
The M33X fits the Monroe ClassicX, UltimateX, 8145X, 8130X, 6120X, 2020PlusX and 122PDX.
Does the M33X fit older Monroe calculators?
No. Earlier non-X models use different ribbons. Check the compatibility chart or call Monroe at 267-580-2600 before ordering if your calculator model does not end in X.
Is this a black-only ribbon?
No. Each M33X cartridge contains a two-color black/red ribbon for compatible Monroe printing calculators.
How often should I replace the cartridge?
Replacement timing depends on print volume, operating conditions and your preferred contrast. Monroe's general recommendation is approximately every two paper rolls when maintaining maximum print darkness is important.
What should I check if the print appears light?
Confirm that the cartridge is fully seated, the ribbon is routed correctly across the print mechanism, the protective shipping piece has been removed and the ribbon advances when the calculator prints. Replace the cartridge if the ribbon is exhausted or has been stored improperly.
