J Brand Lamb Leather Pull Up Legging in Black. - size M (also in ) J Brand Lamb Leather Pull Up Legging in Black. - size M (also in ) 100% dyed lamb leather. Elasticized waist. 12 in the knee narrows to 10.5 at the leg opening. JBRA-WP313. L8007. J Brand proves that the denim movement toward straight and skinny is hardly a trend. With an absolutely clean, anonymous back pocket and sophisticated lines, these jeans are already a classic set for the ages.