https://www.woot.com/offers/portable-rechargeable-massager-for-knee-discomfort Pokytcox Cordless Rechargeable Knee Massager w/ 3-Mode Adjustable Heat on sale for $33.99. Shipping is free for Amazon Prime Members (must login with your Amazon account and select a shipping address in order for Woot to apply free shipping) or is otherwise $6 per order.