Back Pack Vibrator Gas-Powered Model Manufacturer introduces a portable, self-contained backpack concrete vibratorthe gas-powered model 402. It is best suited for remote and hard-to-reach jobs because no electrical cords or pneumatic hoses are required. The device maintains constant vibration in the mix, with easy operator control of vibration speed by the engine throttle. The portable model is available with a choice of shaft lengths and head sizes. The design consolidates concrete 20 to 50% faster. Wyco Tool Co.; 800/233-9926; www.wyco.com