Houston Hard-Hitters: Serval Sliders, Born in 2014. Developed in 2014 by Vester Manufacturing right here in Houston, TX, the Serval Slider was engineered to deliver the hard-hitting power of a liner and packer with the unmistakable feel of a coil machine. Now built by Ruethless Irons at the Vester/Ruethless workshop, this machine continues its legacy of powerful performance. Customize yours: choose your color, connection (RCA or clip cord), and handedness (right or left). Experience the coil-like power of a slider, built in Houston.