The Feeldoe by Tantus is one of the original double dildos that can be used with or without a harness*!
You don't have to be a contortionist for self-stimulation. Feeldoe features a removable vibrator and is made of a harder material for more driving control. It's a completely unique patented toy made of silicone.
*Double dildos require super strong PC muscles when used without a harness. For best results, use in a double-dildo-friendly harness, such as the Joque by SpareParts.