Calling the Catlike Vacuum Helmet the most conventional looking helmet in the 2012 Catlike line would be tantamount to arguing that Cippolini's pink skinsuit for the 2005 Giro was his most conservative wardrobe choice. Granted, it's not as immediately memorable as Catlike's top shelf Whisper Plus the equivalent to Cippo's zebra striped skinsuit, but for many of us, that's probably a good thing. More important though, is that the Vacuum is an economical alternative to the Whisper Plus, while retaining the clean lines, complex technologies, and overall striking aesthetic choices that Catlike is best known for. Like all Catlike helmets, the dramatic appearances aren't without rhyme or reason. Each design is intelligently engineered to enhance the helmet's ventilation efficacy while maintaining the strict safety standards established by CPSC. The Vacuum is constructed around Catlike's Air Tube System, which, similar to the structure of the Catlike Sakana another radical Catlike design that is not currently available on U. S. shores, is a series of small tubes connecting the helmet's segmented 'fins' together. While elegant, the design also cleverly divides the helmet into impact absorbing crumple zones that dissipate energy at the time of a crash not unlike the skeleton of a compact car. These fins strengthen the core structure of the helmet, and allow Catlike's engineers to reduce weight in other areas, giving you a helmet that tips the scales under 300 grams in all three of the available sizes. The fin structure also opens up a wide range of possibilities for ventilation. The Vacuum has 19 generous vents, most of which run lengthwise around the helmet along the Air Tubes. Each forward facing vent has a matching rear exhaust vent to keep a constant and efficient circulation of cool air over your head while you ride. The Vacuum uses the same MPS Multi Position System retention system as the top shelf Whisper Plus. The MPS is constructed around a rubberized pl..