Get Multiple with your New Controller By Michael M on 11/22/2014
Michael M would recommend this product to a friend
You will want to double check, and if you should happen to misunderstand and miss the fact that you need to calibrate in AIR first, you could contaminate this while reprocessing, and wish you had another. You can make your own if you have the right equipment and experiment, and I do, but I want lab-grade references at some point.
You will want more than one with your new system.
Don't pinch pennies now.