Volvo CE manufactures two models of high-frequency, high-amplitude compactors — the DD118HFA (pictured) and the DD138HFA. Through SMART drum technology, both HFA models can be used for a range of applications. Each compactor is engineered with eight amplitude settings that are automatically adjusted to the highest frequency for that amplitude selection. This enables the operator to use lower amplitudes with higher frequency on thinner lifts to increase productivity with decreased risk of damage to aggregate structure or sub-grade, and higher amplitude with lower frequency on thicker lifts and stiffer materials. www.volvoce.com/constructionequipment/na/en-us/Pages/BAHome.aspx