Dealing with slow drains or sewer smells? This Pro Vent anti-siphon trap vent (model 4548 from ES) might be the fix. It's a simple mechanical vent that helps maintain proper pressure in your plumbing system, preventing water from being siphoned out of traps – which is what keeps those nasty odors from coming back up. Easy to install in sink, shower, or floor drain lines. Brand new in package. Ideal for RVs, boats, caravans, or home plumbing where a traditional vent isn't possible. Keep your drains flowing smoothly and your space smelling fresh. UPC does not apply. A handy little device for any DIY plumber or homeowner.