Lex & Lu Grade 23 Titanium Internally Threaded Replacement Head 14 Gauge Threads, 4mm Half Ball, 5mm Disc, 5mm Screw Head, 4mm Heart, 4mm Spike, 4mm Black Spike, 4mm Star. All of our Dermal Anchor Heads are made of the Highest Quality Grade 23 Titanium. Please Remember to Select the Style you want from the Pull Down Menu.