Artisan Power O'Neil MicroFlash 4t, LP3, OC2, OC3, OC4 Printer: Replacement Battery. 2600 mAh Datamax-O'Neil MicroFlash 4t/4tCR, LP3, OC2, OC3, and OC4 Printers: Replacement Battery Replaces OEM battery number 550039-100, 550034-000 and 550030-000 Lithium Ion Rechargeable Battery Pack | 7.4 Volt | Cells Made in Japan | 2600 mAh (44% Higher than OEM battery) Made to prevent battery case split when removes off printer's tight battery compartment. Manufactured by Artisan Power, a leader in premium quality replacement battery packs.