This billet aluminum timing tab has a built-in self-powered LED timing light or car battery hookup. Permanently mounted so there's no need for additional timing lights. The hands free design allows one person to set timing! U.S. Pat. No. 7,503,209.
Features:

• Fits 1955-1997 Small Block Chevy Engines 283-400 Using 8 Inch Harmonic Balancer
• Made from High-Quality Billet Aluminum
• Black Anodized
• 3V Lithium Battery Included
• Sold Individually