A bottle assembly (10, 20), comprising: a bottle (100, 500) comprising a neck (110, 510) having a rim (111, 511) defining an opening (120, 520) into the bottle; and a cap (300, 700) removably coupled to the neck (110, 510), the cap (300, 700) comprising: - an upper cap portion (310, 710) comprising a top (314, 714) and a first sidewall (312, 712) extending around a perimeter of the top (314, 714) from the top to a lower end, - a lower cap portion (320, 720) comprising a second sidewall (322, 722) coupled to the first sidewall (312, 712) and having a distal end (323, 723), wherein the upper cap portion (310, 710) and the lower cap portion (320, 720) define a chamber extending along a longitudinal axis (301, 701) of the cap (300, 700), and - a skirt (330, 730) extending in a radial direction with respect to the longitudinal axis (301, 701) of the cap (300, 700) and configured to be received on the rim (111, 511) of the neck (110, 510) of the bottle (100, 500), wherein the first sidewall (312, 712) comprises a first transverse dimension at the lower end of the first sidewall (312, 712), and the second sidewall (322, 722) comprises a second transverse dimension less than the first transverse dimension, characterized in that the upper cap portion (310, 710) comprises a plurality of convex-shaped protruded segments (316A-C, 716) disposed circumferentially along the first sidewall (312, 712). a bottle (100, 500) comprising a neck (110, 510) having a rim (111, 511) defining an opening (120, 520) into the bottle; and a cap (300, 700) removably coupled to the neck (110, 510), the cap (300, 700) comprising: - an upper cap portion (310, 710) comprising a top (314, 714) and a first sidewall (312, 712) extending around a perimeter of the top (314, 714) from the top to a lower end, - a lower cap portion (320, 720) comprising a second sidewall (322, 722) coupled to the first sidewall (312, 712) and having a distal end (323, 723), wherein the upper cap portion (310, 710) and the lower cap portion (320, 720) define a chamber extending along a longitudinal axis (301, 701) of the cap (300, 700), and - a skirt (330, 730) extending in a radial direction with respect to the longitudinal axis (301, 701) of the cap (300, 700) and configured to be received on the rim (111, 511) of the neck (110, 510) of the bottle (100, 500), - an upper cap portion (310, 710) comprising a top (314, 714) and a first sidewall (312, 712) extending around a perimeter of the top (314, 714) from the top to a lower end, - a lower cap portion (320, 720) comprising a second sidewall (322, 722) coupled to the first sidewall (312, 712) and having a distal end (323, 723), wherein the upper cap portion (310, 710) and the lower cap portion (320, 720) define a chamber extending along a longitudinal axis (301, 701) of the cap (300, 700), and - a skirt (330, 730) extending in a radial direction with respect to the longitudinal axis (301, 701) of the cap (300, 700) and configured to be received on the rim (111, 511) of the neck (110, 510) of the bottle (100, 500), wherein the first sidewall (312, 712) comprises a first transverse dimension at the lower end of the first sidewall (312, 712), and the second sidewall (322, 722) comprises a second transverse dimension less than the first transverse dimension, characterized in that the upper cap portion (310, 710) comprises a plurality of convex-shaped protruded segments (316A-C, 716) disposed circumferentially along the first sidewall (312, 712).