DEREK LAM 10 CROSBY Bell Sleeve Cut Out Shoulder Sweater in Black. - size L (also in ) DEREK LAM 10 CROSBY Bell Sleeve Cut Out Shoulder Sweater in Black. - size L (also in ) The season's trends come full circle with the design of DEREK LAM 10 CROSBY's Bell Sleeve Cut Out Shoulder Sweater. Bare shoulder accents fall into exaggerated bell sleeves to contribute a dramatic feel to this would-be-basic piece.. 85% silk 15% cashmere. Dry clean only. Shoulder cut-outs. Ribbed trim. 10CR-WK33. TR72906CA. Named after the address of the Derek Lam International, LLC headquarters in downtown Manhattan, 10 Crosby Derek Lam is the first ever diffusion line from Derek Lam. 10 Crosby offers accessible styles that are always intelligent and always feature a surprising twist. And true to Derek Lam core principles, each piece upholds value and integrity of design, making every collection look and feel special.