- Jil sander Jil sander 23 new round toe knee-high boots. The upper is naturally rich in unique luster, and the full toe and straight design highlight the Gothic style with inherent temperament. It is simply not too handsome! A must-have item for fall and winter! Upper: calfskin, lining: sheepskin, sole thickness: about 4cm, sole: original foam rubber outsole, size: 35-39 (40 customized, non-refundable),