XTS AR-15/10 Spare Parts Set for 5.56/.223 XTS-SPS XP. Working with these small parts can be aggravating to say the least much less losing one of those pieces. Having the XTS spare parts set includes everything you need and anything you "might" need. Along with saving you the hassle of find a needle in a hay stack. This part set fits 5.56/.223 and comes with a total of 18 parts. Specifications for XTS AR-15/10 Spare Parts Set: Manufacturer: XTS Color: Multi Fabric/Material: Steel Caliber: 5.56x45mm NATO .223 Remington Gun Model: AR-10 AR-15 Features of XTS AR-15/10 Spare Parts Set Material: steel hardened plated. Package Contents: XTS AR-15/10 Spare Parts Set XTS XTS-SPS XP: AR-15/10 Spare Parts Set for 5.56/.223