Step 3- Use a 15/16 socket to remove the air tank nipple
Step 4- Attach double take adaptor using a 14MM socket (Hand tighten threads first, then use 14MM so you don't cross thread or strip the threads) we recommend tightening the center bolt to 125-inch pounds or until tight (DO NOT OVER TIGHTEN).
Step 5- Add the first bottle but not all the way to the valve. Add the second to the same distance. Then use BOTH hands to put them on at the same time. It acts as one single bottle, so you must put them on at the same time!
Blow out the extra lock tight if you would like, but not necessary.