I usually tie the line direct to the Fluorocarbon but when I do use a swivel I use either Spro , sampo or lately these:
Brand: AFW
4.7
4.7 out of 5 stars
(966)
American Fishing Wire Mighty Mini Snap Crane Swivels - 100% Stainless Steel, 3X Stronger Than Brass, Up to 600lb Test -