Dark Storm Industries AR15 Carbine Buffer Spring 5.56mm. Over time the spring in a standard buffer tube loses its effectiveness. As a result you need a spring that will properly and efficiently distribute the load and prevent spring failure. The StormCarbine Spring links the buffer and spring by a series of compression and is a simple way to strengthen the buffer and spring attachment. The carbine buffer spring greatly reduces the fatigue on your buffer tube and springs as well as enhancing the look and feel of your otherwise neglected buffer spring. Specifications for Dark Storm Industries AR15 Carbine Buffer Springs: Manufacturer: Dark Storm Industries Gun Model: AR-15 Length: 11 in Last Chance: Yes Features of Dark Storm Industries AR15 Carbine Buffer Spring For AR15 .223 / 5.56 For Carbine Buffer Systems Approx 11.0" Long Chrome Plated Finish Package Contents: Dark Storm Industries AR15 Carbine Buffer Spring What firearm models does the manufacturer say Dark Storm Industries AR15 Carbine Buffer Springs is compatible with? The manufacturer says that Dark Storm Industries AR15 Carbine Buffer Springs is compatible with AR-15Dark Storm Industries DSI-BFR-SC-556: AR15 Carbine Buffer Spring 5.56mm