Bullard Fire/Rescue Helmet (Black Thermoplastic w/ Quick-Attach(TM) 4 in Faceshield) 10 1/2'' (267 mm) while the disc speed is

while the disc speed is 1725 RPM

It can be driven by a variety of power plants (electric motor

including both hobby and automotive settings

Fan Diameter 12" Fan Speed 3-speeds Max

Bullard Fire/Rescue Helmet (Black Thermoplastic w/ Quick-Attach(TM) 4 in Faceshield) 10 1/2'' (267 mm) while the disc speed isFire Rescue Helmet, Modern, Black, Thermoplastic Shell Material, Fits Hat Size 6 1 2 to 8, Nomex(R) Quick Release and Postman Slide Chin Strap, 4 Point Sure Lock(R) Ratchet Suspension, Includes Quick Attach(TM) 4 in Faceshield, Standards NFPA 1971 2007 Dimensions Fits Hat Size 6 1 2 to 8 Details Item Fire Rescue Helmet Standards NFPA 1971 2007 Suspension 4 Point Sure Lock(R) Ratchet Shell Material Thermoplastic Style Modern Chin Strap Nomex(R) Quick