High grade 316 Stainless Steel Discrete Tactiles with Black Carbide and Clear PlugHead Size: 35mm x 25mm x 4.5mmMaterial on Head: 316 tactile stud with Black CarbideShaft Outer Diameter: 5.8mm (not measuring plug)Shaft Outer Diameter: 8.5mm (with plug)Shaft Length: 12mm (not measuring plug)Shaft Length: 18.5mm (with plug)