The Zackees LED gloves will help you signal when you need to merge into traffic thanks to it's bright LED lights.
These gloves are made from spandex and leather. They can withstand the elements with the batteries in so that means you can use these when riding in the rain. The gloves have a built-in ambient light detector that detect whether it's day or night and adjust the light accordingly. You never have to worry about people not being able to see you trying to merge into traffic.