Compatibility:
• XD 16rd 9mm magazine W/ SP0170
• XDM 19rd 9mm magazine W/ SP0138
• Hellcat 11rd/15rd magazine W/ SP0139
• Echelon full-size 17rd magazine W/SP1102
• Echelon compact 15rd magazine W/SP1102
• SIG full-szie 17rd/21rd magazine 
• SIG compact 15rd magazine

Product Overview:
The Springer Precision extra power magazine spring for your magazines. The extra power spring is essential for reliability when adding any of our extensions to your magazines. For reliable performance, keep your magazine springs fresh.