StackSocial offers the Linearflux LithiumCard 1,200mAh Power Bank in Black for $39.99 with free shipping. (B&H Photo Video charges the same.) That's tied with our mention from September and the lowest total price we could find by $2. This 3x2" power bank features an ultra-thin credit card design, up to 2 amps of charging power, NanoStik pad, and 1,200mAh capacity. Deal ends December 5.