The Texas rockers have used the same tone formula for decades, but when it comes to gear and making a statement, they’re kings of style.

As a gift for Hill, Francis custom-painted a mural of Hill’s hero, Freddie King, on the back of this bass. Francis outfitted the bass with knobs from an old camper, and Francis’ daughter found some rusted metal for the pickguards. Francis says a future project might be painting a B.B. King guitar for Gibbons.

ZZ Top’s guitar and bass tech, Elwood Francis, explains the ins and outs of the newest guitars and basses that Billy Gibbons and Dusty Hill have out on the road for 2015.