Abstract: An adjustable cap comprising a grip and a hub is coupled to the grip. Wherein the grip and the hub are configured to rotate independently of each other and a plurality of legs is coupled to the hub and a lock coupled to the hub wherein the hub and the lock are configured to rotate independently of each other. The lock is further configured to move the legs toward a center of the lock and a cap thread is coupled to the hub wherein the cap thread is configured to move down when the grip is rotated. A plate is coupled to the cap thread wherein the plate is configured to rotate independently of the cap thread. The adjustable cap provides a seal on multiple bottle opening sizes that can be used with a tube to withdraw fluid.