Description Reviews R4 Boro Black or White by Billet Box Vapor. A black or white version of the famous Boro tank for the Billet Box rev. 4 Billet. The tank has a sliding borosilicate glass face allowing easy and efficient filling! All without removing the tank from your Billet Box! Write Your Own Review You're reviewing: R4 Boro Tank - Billet Box Your Rating: Evaluation du produit Nickname * Summary * Review * Submit Review Loading... You submitted your review for moderation.