(12) Genuine Monroe P51S Super Saturated Ribbon Cartridges OEM ribbon cartridge from the manufacturer, not an imitation. 5-year+ shelf life. 1-Dozen Black/Red Calculator Ribbon Cartridges for Monroe Calculator Models: 8130, 8145, 7130, 7140, 7150*, 5130, 5140, Classic, PRO, and Ultimate Extremely Convenient Installation of Ribbons for Monroe Calculator Models Offers Monroes Exclusive True Red Color with Heaviest Inking Saturation on the Market Superior replacement option for ERC02BR Black-Red POS Ribbon, Nu-kote Model BR106N, NuKBR106N, Dataproducts R2087 DPSR2087, and Victor 7011 ribbon cartridges Don&#039;t deal with the mess of getting ribbon ink on your hands, use Monroe&#039;s P51S, a high-quality, easy-to-install ribbon cartridge instead of ribbon spools. Having the highest standards in the calculator industry, Monroe produces the darkest printing black/red ribbon cartridges on the market. Monroe pushed every envelope when designing a ribbon with the highest possible inking degree, and eliminated the risk of ink smudges. Monroe requires their factory to use a true red ink that is extremely rich in color and used specifically by Monroe, unlike the orange tint you see in watered down versions from other brands. Monroe&#039;s engineers developed the most convenient calculator ribbon to install. They created the first-ever cartridge containing a calculator ribbon, which provides you with the easiest installation. To maintain the darkest print on their paper tape, users of Monroe products are suggested to change their P51S ribbon cartridges after replacing 3 paper tape rolls. Designed for Monroe calculators and compatible with other brands and models.