4into1 Uni Filter clamp-on breather 3/8" crankcase breather — washable oiled foam, high-efficiency filtration

4into1 Uni Filter UP-102 3/8" Clamp-On Breather is a clamp-on foam breather that prevents contaminants from entering your ATV engine while allowing free airflow.

The Uni Filter UP-102 is a compact, clamp-on crankcase breather engineered for off-road machines and small engines. It uses open-cell polyurethane foam treated with a tacky filter oil to capture dust, mud and airborne particles that otherwise circulate back into the intake or crankcase ventilation. Laboratory comparisons show Uni Breather foam elements outperform many standard paper breathers in trapping fine particulates while maintaining airflow, making it a practical upgrade for riders who demand reliable protection in dirty conditions.

How does this breather block dirt without restricting airflow?

The UP-102 uses open-cell foam whose pores are impregnated with a specially formulated filter oil. Particles stick to the oiled foam surfaces as air passes through, while the pore structure still permits venting and pressure equalization.

• Open-cell polyurethane foam balances filtration and air passage.
• Filter oil increases particle adhesion without clogging quickly.
• Laboratory testing indicates higher efficiency than many paper elements.
• 3/8" clamp-on fitting installs without modifying housings on compatible engines.

How easy is it to install and maintain on an ATV or small engine?

Installation is straightforward: slide the breather onto the 3/8" tube or vent and secure the clamp. Routine care consists of inspecting the foam and reapplying filter oil when contamination builds up; the foam is washable and reusable when cleaned gently and allowed to dry.

• Tool-free clamp adjusts to a snug fit on 3/8" ports.
• Washable polyurethane foam extends service life.
• Re-oil with a small amount of filter oil after cleaning for optimal capture.
• Simple visual checks detect heavy soiling before performance drops.

Will this breather fit my vehicle or toolbox?

The UP-102 is made for 3/8" diameter vent tubes common on many ATVs, dirt bikes, and small engines; however, confirm your vent size before ordering. Its compact clamp-on design keeps it usable across a variety of layouts without requiring adapters in most cases.

• Designed for 3/8" vent tubes—measure before purchase.
• Low-profile shape fits tight engine bays and exposed roll cages.
• Universal clamp fits a range of aftermarket and OEM vent hoses.
• Lightweight construction minimizes added weight or torque on fittings.

Who is this for? The 4into1 Uni Filter UP-102 suits riders, mechanics and small-engine owners who need a compact, reusable breather that traps fine grit better than many paper alternatives. It’s particularly useful for off-road enthusiasts, utility vehicle operators and anyone who frequently runs engines in dusty, muddy or wet environments and wants a simple, serviceable way to keep contaminants out of the crankcase ventilation or intake path.