Battery Not Included: This set does not include a battery, ensuring you can use your existing compatible batteries without the need for additional purchases. Ideal for those who already own the DO9100 meter and are looking to replace or upgrade components. Digital Display: The digital display feature offers clear and immediate feedback on measurements, ensuring and ease of use when monitoring oxygen levels with your DO9100 meter. Chemical Safety: Contains no high-concern chemicals, making it a choice for both personal and professional environments. This feature ensures that you can use the product in sensitive settings without worrying about harmful substances. Enhanced Visibility: Equipped with a backlight feature, this replacement set for the DO9100 dissolved oxygen meter enhances readability in low-light conditions, allowing for accurate readings anytime and anywhere. Certified Quality: With CE certification, this replacement set meets high standards of quality and safety, ensuring reliability and performance for your dissolved oxygen measurements., Manufacturer: Muuookka