STORE › O-Rings Image 1 of 1 O-Rings $1.00 The O-ring Paco prefers for top performance. 1/16 x 7/16 id neoprene O-ring. Add To Cart Added! The O-ring Paco prefers for top performance. 1/16 x 7/16 id neoprene O-ring. You Might Also Like Tattoo Machine Coils $30.00 Cutback Liner Armature Bar with Springs $15.00 Armature Bar with Shader Springs $15.00 Front Binding Post $10.00 Armature Bar $10.00