Prior-generation waterproof headphones looked upmarket and generally cost a little more, too. H2O Audio's new Flex Headphones ($30) lower the cost of entry to a level anyone can afford, going with four different color options -- pink, green, Super Hero blue (shown), or black -- and promising only three-foot waterproof performance, sweat resilience, and washability. Three silicone rubber ear tip sets are included for proper canal sizing, and a little…
