The new UE Fits wireless earbuds from Ultimate Ears have gel-filled eartips that harden and mold to the exact contours of your ear. The process takes under 60 seconds.

Sometimes a baby's outer ear may be a tad misshapen. Surgery can help later on, but a plastic mold makes the most of the fact that a newborn's ears are pliable. They can reshape within weeks.

It has a rubbery plug for your ear, but inside that plug is a patent-pending soft gel that’s called a photopolymer. That means it’s a plastic that reacts to light. Pushing the tip into your ...