Amazon.com: Stacking Cable for Cisco CAB-STK-E-0.5M FlexStack Cable, Compatible with Catalyst 2960-X and 2960-XR, Stack up to 8 switches, 0.5-m : Electronics
Cisco 2960 Stack Module Comparison
Cisco Catalyst 2960X Flexstack Plus | Stacking module | Optiona
Peter Manton :: Tech Notes: Setting up a Cisco 2960X Switch Stack