A double dildo is a sex toy with two ends designed for penetration rather than just one, as in a regular dildo. This type of toy is most often used to penetrate two different people at the same time, but a someone may also use it for simultaneous anal and vaginal penetration. Other times, someone may choose a double dildo because it provides two different textures for two different sensations within a single purchase.
Double dildos are longer than traditional dildos, and they may be made of a number of different materials, including silicone, latex, and even glass. Many of the ones made of more flexible materials are designed to bend for solo use.
A double dildo may also be called a double penetration dildo or a double dong.