Plug it in, & see if OS X will auto-detect & install the drivers. Check on iomega's website, since they're the manufacturer. Buy with confidence as the condition of this item and its timely delivery are guaranteed under the 'Amazon A-to-z Guarantee'.
Buy Used and Save: Buy a Used 'Iomega Zip 100 Portable USB Drive (PC/Mac)' and save 29% off the $99.00 list price.