We've decided to compare the differences of the DoubleDown (DD) casing and the DH Casing in this following article
Maxxis MTB Tire Sidewalls Explained
Bike Technology - MAXXIS US
Maxxis Summit 2017 - New tubeless DH & Wide Trail plus mountain bike tires, BMX tubeless race - Bikerumor
How to Choose the Right Mountain Bike Tire
Bike Technology - MAXXIS US
Review: The New Maxxis Shorty Gen 2 Tire - This Sequel's Even Better Than the Original - Pinkbike
Maxxis DoubleDown vs. DH Casing - What's The Difference?
Maxxis DoubleDown vs. DH Casing - What's The Difference?
Maxxis Double Down Casing - Is It Really Necessary?
Maxxis Sidewalls Explained EXO vs EXO+ vs DD vs DH
Spotted! New Maxxis DH Tire Makes World Cup Rounds - Bikerumor
Folding Bead vs. Wire Bead MTB Tires
Minion DHR II - MAXXIS US