Callsign Greybeard shows how to install the Pyramex V2G-Plus Integrated Airflow Adapter to a Valken Siera... "Instruction video for installing the Valhalla Airsoft Integrated Airflow Adapter into a Valken Sierra or Pyramex V2G-Plus (including prescription inserts). Watching this instruction video is important to properly install securely and safely into your goggles."