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O'Neill Thermo-X Long Sleeve Crew

O'Neill Thermo-X Long Sleeve Crew 5 5 4

Availability: In stock


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Boost your warmth level with the supplementary O'Neill Thermo-X Long Sleeve Crew. Soft, stretchy and odor resistant, the Thermo is a smart accessory for the savvy cold water surfer. Put the Thermo-X Crew on under your existing wetsuit to dabble into colder seasons or to extend an older suits life until a new one is on its way. A cold nipping layering piece that offers an additional shield of core warming protection, the O'Neill Thermo-X Long Sleeve Crew gives incredible insulation with minimal bulk.

Product Features

  • Maximum core insulation
  • Water repellency, odor resistance
  • 4-Way stretch fabric/li>
  • Boardshort connector
  • Rash protection
  • 50+ UPF
  • Strategic seamless paddle zones
  • Super low neck: no interference with wetsuit neck
  • 210g Nylon/Spandex with HyperDry for maximum insulation and minimal water absorption


O'Neill Thermo-X Long Sleeve Crew warm and softReview by polar bear polar bear
I bought this for my husband for winter polar bear dips here in New England. Friendly quick service... fits perfectly from your chart.
(Posted on 11/21/2019) 2019-11-21
O'Neill Thermo-X Long Sleeve Crew Almost as important as the wetsuit itselfReview by Cheatin5 Cheatin5
I use one of these regularly, along with the shorts. I can usually use a 3/2 when other surfers are in a 4/3. I have comfortably used this and a 4/3 to surf 42 degree water and air temps. Keep it washed or it will develop a funk.
(Posted on 12/30/2018) 2018-12-30
O'Neill Thermo-X Long Sleeve Crew So WarmReview by Luke Luke
This rashguard is so warm under my 4/3 wetsuit in ~60deg water. It is also very light and dries really fast. Very much recommend!
(Posted on 12/20/2018) 2018-12-20
O'Neill Thermo-X Long Sleeve Crew 35x3Review by Goyajoe Goyajoe
Air-water temp.@ wind speed with oneil gear on it don,t matter I stay warm for my session!don,t leave home without it!
(Posted on 12/15/2017) 2017-12-15

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Size Chart

O'Neill Men's Rash Guards — Size Chart

The staff at Cleanline Surf specialize in sizing O'Neill Wetsuits and O'Neill Wetsuit accessories. If you have never tried an O'Neill rash guard before, we strongly urge you to call us for expert advice on sizing. We do have a size chart available below, but please take it with a grain of salt.

XS5′7″-5′9″125-140 lbs36.5-37.5″28.5-29.5″
S5′8″-5′10″135-155 lbs37.5-39″29.5-31″
M5′9″-5′11″155-170 lbs39-41″31-33″
L5′10″-6′0″170-190 lbs41-43.5″33-35″
XL5′11′-6′1″190-210 lbs43.5-46″35-37″
2XL6′0″-6′2″210-230 lbs46-48.5″37-39″
3XL6′0″-6′3″230-250 lbs48.5-51″39-44″



If the product is found to be defective under normal use and proper care, O'Neill will repair or replace the product at our sole discretion. The decision to replace or repair a product is made by the O'Neill Warranty Department after receipt of the defective product. At no time does the O'Neill offer refunds. Defective product should be returned clean and dry, postage prepaid. Please include a note with product description, product defects, requested action, return address (be sure to include postal code, especially for Canadian addresses), daytime phone number with area code, customers name and a copy of the purchase receipt sent to the address below.

Suits without a copy of the purchase receipt will NOT BE COVERED UNDER WARRANTY.


  • Products classified as seconds
  • Fading from sunlight
  • Alterations
  • Materials over 1 year (from date of original purchase), or 90 days for accessories
  • Repairs or alterations done by anyone other than O'Neill or an O'Neill authorized repair facility
  • Warranty request without original receipt


Flat-Stitched Products, Glued and Blindstitched Products, and Fluid Seam Weld Products

  • Limited 1-year warranty (from date of original purchase) on workmanship and materials.

Neoprene Dry Suits

  • Limited 1-year warranty (from date of original purchase) on workman ship and materials (waterproof zipper excluded)


  • Limited 90-day (from date of original purchase) warranty on workmanship and materials


For repairs received from the dealer or end user, O'Neill offers:

  • 10 Business Day Turnaround for warranty Stitched Suits
  • 10 Business Day Turnaround for warranty Glued Suits
  • 20 Business Day Turnaround for warranty Fluid Seam Welded Suits
  • 30 Business Day Turnaround for all Non-Warranty Repairs

Repairs are to be returned clean and dry, postage paid. Please include the name and a daytime phone number with area code, return address, product description, and requested action.

Send Repairs To:

O'Neill U.S. Warranty Repair
1022 Bay Marina Drive, Suite 140B
National City, CA 91950
Tel: 1-800-331-1637


Returns are easy! We understand that in some situations returns or exchanges may be necessary. We also want you to be stoked on your purchase. If you are not 100% satisfied with your purchase you may return it for a full refund, or exchange within 30 days of receiving your order. Items must be in new condition with original tags and packaging.

Please make sure your wetsuit fits before taking it in the water. We are not able to take returns or exchanges on used wetsuits.

Please reference our full Return Policy.

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