These probes work in the same way as those described above but suit a large surface area better. Quad probes can also strengthen jaw muscles. Treatments specifically suited for quad probe applications are Jowl lifts and Gentleman's facials. Jowl lifts improve skin elasticity while removing wrinkles. The Gentleman's facial removes shaving bumps and ingrowing hair. They also hydrated the skin during this treatment. They inject a serum into the probes to aid with electrical conductivity.