When to wear The UPF 50+ Sun Sleeve, created by Crazy Arms® for people who spend a lot of time at the wheel. Harmful UV rays can penetrate car windows, creating a risk of skin damage to the exposed arm. Product Details Premium Italian fabric Made from recycled yarn* Soft feel ARPANSA tested UPF 50+ (blocks over 98% over UVA and UVB rays) Light-weight (140gsm) Breathable Quick drying Two-way stretch for perfect fit 90% Recycled Polyamide (Econyl®); 10% elastane (Lycra®) Gentle elastic band at top to hold in place Side seam, with thumb hole, and incorporating woven Crazy Arms® label Made in Australia * The fabric is made from ECONYL®, a regenerated nylon coming from ghost fishing nets recovered from the ocean, and other nylon waste. Available as a Single Sleeve or Pair Size Guide Regular Fit: for people with a bicep measurement 22 - 30cm Relaxed Fit: for people with a bicep measurement 30 - 36cm* Crazy Arms are designed to fit like a second skin for athletic activity. This should feel a little tight on first wearing, but will ease to a snug fit after one or two wears.* For customers up to 32cm bicep measurement, if you are using Crazy Arms for sports with high arm movement (eg golf, tennis, cricket, sailing), the Regular size is our recommended option to ensure the sleeve stays in place. We offer a free size exchange on sizes for un-worn Crazy Arms. For more information on sizing, click here.