External Testing Certification NSF, ANSI. 𝐄𝐚𝐬𝐲 𝐢𝐧𝐬𝐭𝐚𝐥𝐥𝐚𝐭𝐢𝐨𝐧: It only takes a twist to replace the filter in three seconds. No tools required. Unit Count 1.0 Count. Compatible Water Purifier Models Waterdrop WD-G3P600, Waterdrop WD-G3P800-W, Waterdrop WD-G3-W.