Many GM brakes use a heavy single spring, the 50600 engages the spring and quickly releases the spring tension. 2 piece construction - releases tension on both large and small GM single spring brakes during servicing. Saves time when servicing brake shoes, the emergency brake cable or the brake cylinder Many GM brakes use a heavy single spring. The 50600 engages the spring and quickly releases the spring tension. The brake can then be disassembled to replace brake shoes, emergency brake cable or service the brake cylinder. Applications include: Smaller spring 1991 to current GM Bonneville, LaSabre, and Delta 88. 1992 to current GM Buick Electra, Olds 88, Cadillac Fleetwood, Cadillac DeVille, Chevrolet Lumina APV, Pontiac Trans Sport, and Olds Silhouette. 1995 to current Chevrolet Lumina and Monte Carlo. Larger Spring 2005 to current Chevrolet Silverado, 2004 to current Chevrolet Colorado.