Delta Scientific
Bollards
Delta’s pneumatic bollards are 60 percent more efficient and cost-effective than electro-mechanical units. They are aesthetic, durable, flood-resistant and green, using low voltage and current draw and providing up to 300 cycles per hour. Customers needing all-weather, crash-resistant bollards are turning to pneumatic designs versus more expensive electro-mechanical devices. Crash rated and tested with a 15,000 lb vehicle going 50 mph, Delta's pneumatic bollard systems operate individually or in groups up to ten and are used for intermediate level security applications.
http://deltascientific.com/hs_bollards.php