The LUXE Merino Arm Warmer runs the same lightweight merino fabric as the Luxe Merino Jersey, built up to a 170g mid-weight blend for extra warmth without losing that fabric's next-to-skin feel. Flatlock seams keep the fit smooth under a jersey sleeve, so pairing the two never means fighting bulk at the shoulder. What Our Gearhead(R) Experts Are Saying:"I paired these with the Merino Jersey on a cold start that warmed up fast, and rolling them down at the wrist took seconds without breaking stride. The fabric matched close enough that I forgot I had two separate pieces on."