Amazon has the very popular, Photive Hydra Wireless Bluetooth Speaker available right now for just $17.96. This is down from its original price of $29.94. Amazon's website does still list it as $29.94, in order to drop the price, you need to use the promo code 400HYDRA at checkout.
This Bluetooth speaker from Photive is actually pretty good. It has over 4,800 reviews on Amazon, amassing an average rating of 4.5 stars out of 5. This is a waterproof speaker, so you can take it with you into the shower and listen to your favorite tunes, you can also take it to the beach or to the pool. Now this is a Bluetooth speaker, so it does have support for Bluetooth 4.0, unfortunately no support for WiFi. It also has battery life rated at around 8 hours on a continuous charge. Finally, the sound quality on the Photive Hydra is really impressive, especially given its size. You'll be blown away by the quality as well as the volume.
This item is also eligible for Amazon Prime's free shipping. Which includes free two-day shipping, and pretty cheap next-day shipping if you need it here extra fast. If you are not an Amazon Prime member yet, you can sign up for a free trial of Amazon Prime by hitting the link below. You'll get 30 days free (if you're a student, you get 6 months), and then it's $99/year. Prime members do get a whole lot more than just free shipping though, so be sure to check out the full benefits. Remember that if you are looking to pick this up as a gift for someone this holiday season, you'll need to order it by December 18th for non-Prime shipping, and if you are a Prime member, you have until December 22nd, to get it in time for the Holidays. Amazon does also offer extended returns for anything purchased before December 31st, can be returned until January 31st, 2018.