AEM No-weld exhaust clamp is the easiest way for you to add a air/fuel ratio gauge or an additional oxygen sensor to your existing exhaust system without welding. This stainless steel clamp has a O2 sensor bung welded to the clamp (18mm thread). Simply drill a hole into your exhaust pipe, install the gasket around the hole, slide on the clamp, tighten the bolts, and your done. It's that simple. Available in 4 sizes, this clamp has a 2.25" to 2.50" inside diameter.