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O'Neill Hammer 1.5/1mm L/S Crew

Sale: $36.95 (46% off, was $68.95)
2 Reviews
O'Neill Hammer 1.5/1mm L/S Crew - black/black/black - view large
Color: black/black/black
Size: Size Chart
Color: black/black/black
In Stock - Qualifies For FREE U.S. Shipping
The O'Neill Hammer 1.5/1mm long sleeve crew offers unrestricted movement in any direction. O'Neill used Flatlock seam construction for a comfortable fit and strategic seamless paddle zones to prevent chafing in high-friction areas.
Max Thickness
  • 1.5mm
  • Long Sleeve
  • No Hood
  • Flatlock
O'Neill Technology
  • 100% UltraFlex DS
Max Thickness

The warmth of a wetsuit largely depends on the thickness of its neoprene. Measured in millimeters (mm), a thicker suit will generally keep you warmer. However, a thicker suit will also weigh more and be less flexible, resulting in greater paddling fatigue and reduced performance. The goal is to choose a suit that is not unnecessarily thick for your local conditions.

To achieve a balance between warmth and performance, most wetsuits use a combination of neoprene thicknesses. Thicker panels are generally used in the chest, back, and lower body, while thinner panels are used through the arms and shoulders for greater flexibility and easier paddling. A suit’s particular combination of neoprene thickness is reflected in the name of the suit itself. For example, a “4/3mm” wetsuit uses both 4mm and 3mm neoprene. A “2mm” wetsuit is made entirely of 2mm neoprene. The thickness we list here refers only to the thickest neoprene used in the suit. More detailed information on the thicknesses used and their placement is listed below.

Keep in mind that additional features such as advanced seam construction, insulated lining, and hoods greatly impact the warmth of a wetsuit. The presence of these features can compensate for the reduced warmth of thinner neoprene, offering greater performance while retaining overall warmth. For example, a higher-end 4/3mm wetsuit with sealed seams and interior thermal lining will likely stay as warm as an economical 5/4mm wetsuit that does not have those features.


In a perfect world, wetsuits would be seamless. Until then, the goal is to make seams as light, flexible, durable, and impermeable to water as possible. While each brand has its own lingo, there are four basic seam constructions on the market: flatlock; glued and blind stitched (GBS); glued and blind stitched with taping; and liquid rubber seam seal.

Flatlock - A durable, breathable, and economical seam construction where two panels of neoprene are overlapped and stitched together using a flatlock stitch. Flatlock seams are often found on warmer water suits and neoprene tops where absolute waterproofing is not critical or necessarily desired.

O'Neill Technology

100% UltraFlex DS - Super flexible, soft Neoprene that provides 4-way stretch for unrestricted movement in any direction.

Overall Rating
Reviewed by 2 customers

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Good stuff
by Joseph Freitas in Mililani, HI (Verified Buyer)
Posted on 10/16/2016
O'Neill Hammer 1.5/1mm L/S Crew - black/black/black
Again O'Neill gear great fit very soft and light and flexible
0 person has found this review helpful
If in doubt, go with the smaller size
by Matt P. in Eugene, OR (Tactics Employee)
Posted on 6/5/2013
O'Neill Hammer 1.5/1mm L/S Crew (Closeout) - flint/black/white
I needed to pick one of these up for a recent warm water trip. I wear a medium wetsuit. I tried on both the medium and the large and the medium felt way too tight, so I went with the large. Lesson learned. With so many water access points, you want your neoprene top very snug to help prevent the water balloons forming down your arms. So O'Neill had it right and I should have stuck with my normal wetsuit size.
1 person has found this review helpful

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