Review on Expandable Elastic Men's Collar Stays - Premium Extender for American Accessories by Julian Rash

These things work well and not only lengthen the collar but also make it stretchy thanks to the elastic. When you turn your head, your collar flexes a little, making it comfortable in multiple positions. I would give 5 stars but I think these things are overpriced for what you get. I haven't tried it more than once or twice so I don't know how they hold up over time.