Copy-paste these into the CET console:
Game.AddToInventory("Items.spiked_collar")
Game.AddToInventory("Items.spiked_collar_white")
Game.AddToInventory("Items.spiked_collar_pink")
Game.AddToInventory("Items.spiked_collar_gold")
Game.AddToInventory("Items.spiked_collar_holo")