NVX Audio XBTL6 Bluetooth On-Ears for $30

NVX is better known for their XPT100 Studio Headphones (currently $80), but they have other models as well, such as their NVX Audio Bluetooth On-Ears, model XBTL6, currently going for $30 fulfilled by Amazon. The (new) usual free shipping terms apply at Amazon (Prime or $49+ or $25+ in books).