Motor Size: 18mm (diameter) x 27mm (L). Easily change stroke length with stroke adjustment knob. Locking mechanism prevents stroke from changing mid-session. Stroke Options: 2.4mm, 2.7mm, 3.0mm, 3.3mm, 3.6mm, 3.9mm, 4.2mm.
Comes with 2 O-rings, 1 spring, 1 allen key, 1 drive bar, and 1 wheel cam.