STEP 1: Place Rubber O-RingsPlace two rubber o-rings on both the female and male fitings of the shower filter. | STEP 2: Flush Shower FilterFlush shwoer filer to fush out carbon powder in the activated carbon of the cartridge. | STEP 3: Install With Teflon TapeWrap teflon tape tightly around the threads of your shower filter and shwer arm. | STEP 4: Twist On Shower HeadTwist on shower filter and shwer head, then turn clock-wise to tighten by hand. |