Update (10/2 11:00am): We also spotted the Cambridge SoundWorks OontZ Angle 2 Bluetooth Speaker (multiple colors) at Amazon for $26.99 Prime shipped (Reg. $35).
Omaker Official via Amazon offers its M4 Portable Bluetooth Speaker in orange or green for $34.99. Applying coupon code OMAKERM4 drops the final price to $18.99 with free shipping for Prime members or on orders of $35+. This is good for 45% off the original listing, a match of our previous mention and the lowest price we can currently find.
We positively reviewed the Omaker M4 shortly after its release:
The M4 is easily one of the best low cost speakers out there. It sounds more like a $50-100 speaker from a big brand but adds water resistance and ruggedness. I dropped mine a few times without even getting a scratch. They are like the superball of Bluetooth speakers.
Amazon customers largely agree, rating this Bluetooth speaker 4.5/5 stars. Features include Bluetooth 4.0 and NFC connectivity, 12 hours of playback on a single charge, and it is IP54 rated with a splashproof design for the shower or outdoor activities.