Petite purple puff. The Duo is a slim, portable, color-blocked wonder designed by the Florida studio Yield — it's bigger than a standard single-smoke pipe, but small enough to keep herbs snugly inside its bowl. And its lab-quality borosilicate glass does not conduct heat, making for a cooler, smoother smoke. Materials 2.5" l x .35" dia shaft, .6" dia bowl Borosilicate glass About Tetra Tetra curates lifestyle accessories for an elevated smoking experience, combining aesthetics, safety and functionality. Founded by Monica Khemsurov and Eviana Hartman, Tetra specializes in designer smoking objects that seek to revive iconic mid-century techniques with elegant, contemporary style.