According to market research found that many businesses on the market to promote a lot of rotary barrier, but the industry qualified and qualified qualified businesses rare, mostly filled with foam, there are a lot of security risks. While this fence, R & D organizations using EVC and a dozen new polyurethane composite material barrel form, is not only safe and beautiful. According to the Beijing crash test analysis, single barrel rotation is not large, that is, unloading effect is not good, but a simple buffer effect. Division I professional R & D team on the basis of the new research and development of the double barrel rotary fence, a column up and down two barrels. According to the analysis of the experiment, the impact of small vehicles in the next barrel, large vehicles hit the vat. This invention designed by ten national invention patents, the market is certainly big, we hold one of the greatest pride.