Sprinco 4-Coil M4 Enhanced Extractor Spring Upgrade Kit SKU ES-4COIL $4.95 In stock Quantity: 1 Add to Bag Product Details Sprinco USA 4-Coil M4 Enhanced Extractor Spring Upgrade Kit The 4-Coil spring features equivalent strength to the Gold spring, but much longer life due to the material and processing. This will last the life of the bolt in most applications. The pack includes 4-Coill spring and mil-spec black extractor spring insert Made in USA Save this product for later Favorite