The Multi-function MTL Drip Tip (No Polished) is made of PC (Mouthpiece) and Stainless Steel (510 Base). The set includes two short type mouthpieces (Height: 13mm; Outer Diameter: 8.5mm; Inner Diameter: 3.5mm), two long type mouthpieces (Height: 23mm; Outer Diameter: 8.5mm; Inner Diameter: 3mm) and a 510 Base (Height: 6.5mm; Outer Diameter: 11mm).