Will this work on my existing roof rack?

Universal design mounts to standard roof rack crossbars. Verify your roof rack has crossbars spaced to accept the carrier's mounting footprint before ordering.

Do I need straps or tie-downs to secure the kayak?

Carrier assembly provided does not include additional straps—plan for heavy-duty ratchet or cam-buckle straps rated for kayak weight and your vehicle's speed limits.

What's the difference between this and two separate single-kayak carriers?

This 4-piece set is engineered as a paired system for balanced load distribution and simplified setup. Single carriers require doubled hardware and independent tensioning.