Amazon offers its AmazonBasics Portable Wireless Bluetooth Speaker
in Black for $35.99
with free shipping
. That's $4 off list and the lowest price we could find. It measures 7.3" x 2.4" x 2.8" and features a 150Hz to 20KHz frequency response, 30-foot Bluetooth range, two 3-watt speakers, microphone, 3.5mm auxiliary port, and rechargeable battery with up to 15 hours of music per charge.