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- USA
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Ships within 48 hours · Estimated delivery Jul 13 - Jul 18
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Description
Flowmonster Performance Muffler 3 in Dual inlet & outlet 12599-FM 409 StainlessOverview The Flowmonster series of absorption style mufflers deliver a moderate tone for the enthusiast looking for a deeper, more aggressive exhaust note than most OE (Original Equipment) mufflers, unlike the racey exhaust note associated with "chambered" style mufflers. Interior construction features 3. 50 inch "straight through" perforated 409 stainless steel tube surrounded by high temperature sound absorption packing material which helps to
Overview
The Flowmonster series of absorption style mufflers deliver a moderate tone for the enthusiast looking for a deeper, more aggressive exhaust note than most OE (Original Equipment) mufflers, unlike the racey exhaust note associated with "chambered" style mufflers.
Interior construction features 3.50 inch "straight-through" perforated 409 stainless steel tube surrounded by high-temperature sound absorption packing material which helps to deliver a deeper, mellower exhaust note. The internal design is reversible allowing the flexibility to be installed in either direction to best accommodate fitment with the intended vehicle. The fully MIG-welded 409 Stainless Steel material is embossed with the "FLOWMONSTER" logo on the case.
Interior construction features 3.50 inch "straight-through" perforated 409 stainless steel tube surrounded by high-temperature sound absorption packing material which helps to deliver a deeper, mellower exhaust note. The internal design is reversible allowing the flexibility to be installed in either direction to best accommodate fitment with the intended vehicle. The fully MIG-welded 409 Stainless Steel material is embossed with the "FLOWMONSTER" logo on the case.
Features:
- 409 Stainless Steel construction for superior corrosion resistance and good looks
- Interior construction features high-temp interior sound absorption material delivering a deeper, mellow exhaust tone
- Perforated High-Flow straight-through tube design for increased exhaust flow
- Moderate increase in interior tone over most OE mufflers
- A stainless steel performance muffler at an economical price
- Internal Design is reversible allowing flexibility to be installed in either direction
- Sold Individually
- This is a Universal Fit muffler - Not a Direct fit. Some adaption may be required for proper fitment on some applications
| Body Height (in) | 5 |
| Body Length (in) | 22 |
| Body Width (in) | 11 |
| Finish | Natural |
| Fitment | Universal |
| Inlet Connection Type | Pipe Connection |
| Inlet Inner Diameter (in) | 3 |
| Inlet Outer Diameter (in) | 3.13 |
| Inlet Position | Dual |
| Material | 409 Stainless Steel |
| Muffler Series | Flowmonster |
| Muffler Type | Absorption / Glasspack |
| Outlet Connection Type | Pipe Connection |
| Outlet Inner Diameter (in) | 3 |
| Outlet Outer Diameter (in) | 3.13 |
| Outlet Position | Dual |
| Overall Length (in) | 28 |
| Reversible | Yes |
| Shape | Oval |
| Sound Level | Moderate Sound |
| Type of Muffler | Absorption |
| Part Number | 12599-FM |
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.0 ★★★★★
Based on 712 reviews
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Product Reviews
★★★★★ 5
Soft material
Size: X-Small, Color: Dark Indigo Wash
Looks beautiful and is very soft
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 5, 2026
★★★★★ 5
Soft and lightweight
Size: XX-Large, Color: Light Denim Blue, Size: XX-Large, Color: Light Denim Blue
Great lightweight jacket more like a shacket really. Fits my son nice as well. So soft.
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Reviewed in the United States on March 21, 2026
★★★★★ 4
Thin
Size: XX-Large, Color: Medium Indigo Wash
it's good but very thin.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 26, 2025
★★★★★ 5
Nice jacket!
Size: Large, Color: Dark Indigo Wash
I got this coat for my nephew because he has been begging for a similar one and he loves it! The sizing is dead on and the fabric is a little stuff so size up if you think you'll need to. Great quality, well made!
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Reviewed in the United States on May 11, 2026
★★★★★ 5
Great quality!
Size: 2T, Color: Dark Indigo Wash
Decorated with name on back and flowers on front. She loves it!
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Reviewed in the United States on April 20, 2026