Traffic road-block, 1) adjustable trestle can be opened and closed 2) anti-corrosive and sharp steel nails on the trestle 3) glue covers nails to ensure safety 4) the air pressure of the tire can separate the nail from the trestle 5) gas released within 30 seconds 6) max intercepted length:5m 7) intercepted width:185mm 8) total thorns:120/170pcs 9) thorn length:40mm 10) weight:17kg 11) pedestal material: PA + PE 12) thorn material: Stainless steel tube