Since the 1920's RIMAC has been the industry golden standard for valve spring testing of precision engines by hardcore builders and enthusiast alike. Even post-WWII era models are still coveted by them as is evidenced by nearly $1,000 price tags on auction websites. Now, the Rimac brand has returned with the quality, reliability, and standards that made it a legend in the engine building world in the first place. Spring shown in product images is not included.