Actually, Betta fish are tropical fish that do require a steady temperature of 76 to 86 degrees, with the ideal temperature range at 78 to 82 degrees. Betta fish that are exposed to cold water can suffer from loss of immune response, loss of color, and illness. In addition to the lack of heating capable in these tanks, there is no easy way to change the water and maintain water quality. Clear water is not a sign of clean water. Ammonia is the # 1 killer of fish. It is an invisible chemical released through fish exhale, poop, and uneaten food. If the tank is not going to be wired for filtration, then it should have more frequent water changes in order to ensure water quality. Overall, these tanks do not benefit the animal and are more akin to keeping a dog locked in a tiny cage for it whole live. The animal can survive but it will not thrive.
The vodka bottle design is particularly terrible for the fish. This is animal cruelty.