Groupon offers the Western Digital My Passport Air 500GB USB 3.0 Hard Drive (Refurb) for Mac on sale for $39.99 with free shipping. This comes with a six-month warranty from Western Digital. Deal ends soon!

What makes this deal hot:
You save 73% off the retail list price after instant savings.

What this does & Why you need it:
The Western Digital My Passport Air features 500GB capacity, Fast USB 3.0 connection, Compatible with Mac OS X, Works with with Apple’s Time Machine backup software, Durable anodized aluminum enclosure, Password protection keeps your files secure, USB-powered, and more