Compact & Lightweight Sign Stands for Roll up Temporary Work Zone Signs, Warning Signs, and Regulatory Signs. Bone Safety SafeZone Stands are NCHRP-350 certified making them tested and approved for use on the national highway system SZ-412-2S Dual Spring Stand SZ-412 Springless Stand SZ-412-S Single Spring Stand SZ-460 & SZ-484 Springless Sign Stands SZ-460-2S & SZ-484-2S Dual Spring Stand SZ-312 & SZ-312-E Springless Sign Stand SZ-412-X (Ridged) Fixed Leg Stand SZ-RBS Rubber Base System Catapult Springless Sign Stand