Specifications include, but are not limited to: The roller shall be a 66 inch minimum wide drum, articulating tandem, self-propelled type with a built-in vibratory system developing a minimum of 11 tons force per drum in asphalt pavement. Units supplied to this specification shall meet or exceed these requirements. PERFORMANCE: 4.1. Drum vibration frequency – selectable, up to 50 Hz minimum. 4.2. Vibration amplitude: 0.04 inch maximum 4.3. Maximum compressive force per drum (static + dynamic): 22,000 lbs. minimum 4.4. Maximum compressive linear load per drum (static + dynamic): 250 lbs/in minimum 4.5. Articulation / Oscillation: +/- 28 degrees minimum / +/- 8 degrees minimum 4.6. Travel Speed: 6 mph minimum 4.7. Both drums must perform vibration and oscillation.