Improve the Grip and Appearance of Your 1911 with this Wilson Combat Full-Size Mainspring Housing. The addition of Wilson Combat's steel Checkered (20 x 30 LPI) Mainspring Housing is a great way to improve the grip and appearance of your 1911 Auto. You'll be amazed at the quality of this part. It's fully machined from bar stock with real cut checkering. The checkered mainspring is a great drop-in enhancement. Low luster glass bead finish. 20 x 30 LPI Checkering Blued finish Fully Machined from Bar Stock with Real Cut Checkering Low Luster Glass Bead Finish Drop In fit for most full size 1911 handguns Minor fitting may be required in some guns