Collar of Health (3.5e Equipment)
From D&D Wiki
Collar of Health: This collar is a golden disk on a chain. It usually bears the image of a bear or other powerful animal. The collar grants the creature an enhancement bonus to Constitution of +2, +4, or +6. It is worn around a creatures neck. Can be used on a Familiar, a Druid's Animal Companion, or a Paladin's Mount.
Price: 4,000 gp (+2), 16,000 gp (+4), 36,000 gp (+6)
Moderate transmutation;CL 8th; Craft Wondrous Item, bear’s endurance.; Cost 2,000 gp and 160 exp(+2), 8,000 gp and 640 exp(+4), 18,000 gp and 1,440 exp(+6); Weight: - lb.; Market Price: Varies