Endura's Pro SL PrimaLoft Gilet II is designed with your ride in mind, and it works to warm your core temperature without the risk of overheating. It's designed for longer rides, and that makes sense considering the brand is known for its long-haul gear. We love that it packs away into jerseys with medium-to-large pockets, but the Pro SL has everything you need to carry your supplies too. It's designed with windproof panels and PrimaLoft Gold insulation that works to balance a lightweight feeling while warming your core. It works as a layering piece, but that doesn't mean it adds bulk. It's a slim cut and an athletic fit that remains close to the body, and it's a great option when you need a little extra insulation.