ESB mechanical timer knob and timer overlay decal sticker. Replacement timer knob and overlay for ESB tanning beds with a twist-style mechanical timer. Black plastic knob with an orange indicator marking. New factory replacement part. Part # 310008 Knob Measurements: .234" Stem Diameter .180" on the flat spot. Fits: ESB, Solar Wave, and Solar Storm with "twist-style" timers. *I also have other Solar Storm, Solar Wave, ESB replacement parts, manuals, and tanning accessories that are not listed in my store so just ask if you need something not listed and I can list it. **If you use the CART feature, shipping charges can be combined if you are purchasing multiple items in different categories.