This blue UR3 stroker is the Optimale Vibrating Stroker w/Thick Ribs. The simplicity in design sometimes understates the intensity of the action when it is working on your member. Aside from the amazing UR3 material, the inner canal is lined with thicker ridges compared to the usual that you find on common strokers and they are absolutely sensational. Doc Johnson also does not leave it at that, a bullet vibe is also built-in right at the head and it is at the perfect spot for your thumb to activate it. The unit measures 5 inches, the canal is 4.8 inches deep and 2.3 inches wide.