The Agency Arms G17 Compatible 9mm +5 magazine extension is designed for 17rd magazines (Will not work with 10rd magazines).

• Fits GLOCK G17/17L, 19X, 34, 45 Magazines
• Machined from 6061 MIL-A-8625 Type 3 Hard Anodized
• Dot Matrix Panel for Marking
• Chrome Silicon Alloy Spring
• Increases capacity by 5 rounds (9mm), 4 round (.40s&w & .357)
• Extended Ledge for one-handed manipulations
• Made in the USA