Lululemon Back In Action Long Sleeve Shirt Yachtie Stripe Pink Pastel White. Estimate size of 2 or 4, no size tag. Estimate is based on measurements. Pit to pit is about 22.75”. classic long sleeve you'll reach for again and again. The scooped back hem adds length when you want a bit more coverage. pima cotton Pima Cotton fabric is breathable and soft against your skin features Designed for: On the Move Lycra®: Added Lycra® fibre for shape retention Relaxed fit: Gives you room to move without restriction Coverage: Longer in back