Ilse Jacobsen - Chelsea Rainboots (Rub30C) - ArmyThese handmade Chelsea rubber boots can withstand even the hardest torrential downpour. The Ilse Jacobsen boots are made from the finest single estate natural rubber from sustainable harvests. This pure, natural rubber is mixed with a secret recipe, making the fundamental composition 52% pure, natural rubber and 48% secret recipe. Entirely PVC free, our boots contain no animal by products. The result is a sturdy and reliable companion for rainy days.