9mm Commercial Wetsuit Jacket - Titanium Mega-Stretch Sealed Seam in size medium - which fits approximately a size 8 female, to M male. 
 
As an instructor that dives all year round in 11-20C waters, this is my go-to in colder months, paired with 5-8mm bottoms. In warmer 16-21C temps, it's perfect with 3mm bottoms, dive tights or on it's own! 
 
The 9mm Commercial Wetsuit is a high-quality long-sleeved wetsuit, essential for when diving in cold water demands warmth, comfort and the best fit.  
 
With titanium lining, the wetsuit keeps off the windchill, one of the most important factors in staying warm in between dives.