Leather Spiked Collar Black 1x20"Circle T Tanned Leather Spiked Collar Black 1x20" Coastal's handcrafted Circle T Oak Tanned Leather Spiked Dog Collar offers rich color that becomes even more beautiful with age and is embellished with traditional spikes and spots to add a little edge. Made from full grain leather, this top quality collar is vegetable tanned using tree bark to achieve excellent leather character, and the hides are dyed for luxurious color. The Circle T Leather Collar