The list of free items included in the DLC:

Female Costumes
Hawaiian Swimsuit(F) - 14 days
Seaside Swimsuit(F) - 14 days

Male Costumes
Hawaiian Swimsuit(M) - 14 days
Seaside Swimsuit(M) - 14 days

Unisex Items
Ice Cream - 7 days
Sunscreen - 7 days
Supersoaker - 7 days
Snorkel - 14 days
Sharkbite Surfboard - 7 days
Radical Surfboard - 7 days
Retro Surfboard - 7 days
Magma Surfboard - 7 days
Hawaiian Surfboard - 7 days
Jungle Surfboard - 7 days
Beach Ball - 7 days
Beach Umbrella - 7 days