Every Silver Surfer™ Herbal Vaporizer-Electric Candle is different and can be customized to your personal taste. Your SSV will have its own, free, unique, custom handmade glass marble temperature knob. Yes, we went above and beyond the competition by hand blowing our glass knobs. No other company goes to these lengths. The SSV also features a uniquely colored heater cover to offer an even more custom look at a reasonable price.