The Machined screen and extra balls (sold separately) are so you can now take out your twist core, put a single 1.5mm machined screen in its place, and it will now hold about an extra 100 rubies. This will now turn the Ruby Twist into a straight airflow style diffuser that some may prefer over the Twist.   This allows for larger rips and more heat calories!  Made from 316SS.

Ruby twist head assembly ans coil shown for demonstration. ONLY the machine screen is included in this purchase.