Aqueon ProScraper 3.0 Twist & Click Plastic Blades work with any Aqueon ProScraper 3.0. Replacement blades are a great option for when current blades become dull or worn down. No need to replace your whole scraper. These blades are great for acrylic or delicate glass aquariums because of the softer material, reducing the risk of scratching. The Twist & Click design makes it easy to switch your blades or replace them when they become worn. To change the blade, click out the tabs from the head, twist blade and remove. To replace the blade, insert blade at an angle, twist and click in the blade tabs to lock into the head. For acrylic or delicate glass aquariums. The softer material reduces risk of scratching. 3 Pack. For use with any Aqueon ProScraper 3.0 Aquarium Algae Scrapers. To Change Blade: Click out the tabs from the head, twist blade and remove. To Replace Blade: Insert blade at an angle, twist and click in the blade tabs to lock into the head.