Double-ended dildos are commonly made from silicone, TPE, PVC, and glass. Silicone is the best choice for most users because it is soft, flexible, hypoallergenic, and body-safe, making it easy to clean and comfortable to use. TPE and PVC are softer but porous, so they require more careful cleaning and are less durable. Glass double-ended dildos provide a firmer sensation, and they can be heated or cooled for temperature play. Silicone is typically preferred for its safety, flexibility, and durability.