Extensive Compatibility: (not compatible with i series, 900 series!!!). Works perfectly on Nimh Suitable for Roomba models: 894 880 871 870 866 864 861 800 790 785 770 765 761 760 700 694 691 660 655 654 651 650 645 635 632 631 630 625 620 610 605 600 595 590 585 581 580 570 565 564 562 561 560 555 550 545 540 536 535 530 525 520 516 510 500 and more.（tip：After receiving the battery, please fully charge it before use） Upgrade to Lithium Battery Now: Not just a replacement, our high capacity Li-ion battery Suitable for roomba replacement parts is designed to improve your experience Compatible with Roomba by extending the vacuuming time from less than a hour to at least 2 hours on a single charge. Now your vacuum cleaner won’t have to be charged multiple times for one cleaning job. Upgraded in Longevity, too: Besides delivering longer runtime, the Melasta lithium battery Suitable for Roomba is also superior in longevity thanks to the 800 charge cycles brought by its’ Li-ion cell, making it sustainable for 1-2 years — a huge improvement compared to NiMH batteries that typically last for only a few months. Safety Assured: One of the few battery cell selection with UL cetified in the market of Compatible with Roomba replacement batteries, equipped with battery management system(BMS) that can effectively protect the battery from potential damage caused by short circuit, over-charge/discharge, over-voltage and over-heating. After-Sales Support:Includes a 30-day return window under Amazon’s standard return policy and a 12-month product support period.Email support is available.If you have any questions, you can contact us through the “Your Orders” section of your Amazon account for product assistance.Manufacturer support is available for product-related inquiries.