"A standard bridle. The design doesn't really stand out, which is why it's well suited to any type of horse. A favorite among peddlers and travelers alike."
Breath of the Wild
The Traveler's Bridle can be obtained by scanning a Link (Rider) amiibo, through the use of the amiibo Rune. Scanning the amiibo will drop various items from the sky, along with a treasure chest, which has a chance of containing the Traveler's Bridle, but can also contain different items. The amiibo can only be scanned once per day.
Just like all horse gear items in the game, this gear part does not provide protection for the horse, and it serves mainly cosmetic purposes.