In plushy, squeezable elastomer, the Dualistic bends and flexes for perfect positioning, but it's absolutely firm enough to satisfy. Which shaft you choose to use where is entirely up to you - the thicker shaft stands a little straighter, while the the slimmer one works for harder-to-reach places. You can, of course, play with one at a time, or take advantage of both for that true DP experience.  
However you choose to play, the option to go handsfree is on the table (or counter, or shower wall) thanks to a sturdy suction cup base. The Dualistic can also be enjoyed with many harness or strap-on systems.
In body safe TPE (elastomer) that's a breeze to clean and maintain, the Dualistic should be washed well before and after playtime. Use lots of warm soapy water ort a good toy care fluid/foam to keep it squeaky clean and ready for action. The Dualistic is compatible with any favourite water-based lube - use lots for maximum slip 'n slide.
* Featured measurements list the thicker of the Dualistic's shafts. The thinner is about 4.5"/11.4cm penetrable and 1.4"/3.6cm at widest
Features
Length: 8.5"
Insertable Length: 6"
Girth: 5" at largest point
Width: 1.5" at largest point
Materials: Thermoplastic Elastomer
Special Features: Phthalate-Free, Suction Base, Textured Surface