ISMI Self-Defense Spring Kit for Glock GEN 1-4

Designed to fit Glock Gen 1-4 Models: G17, G19, G20, G21, G22, G23, G24, G25, G26, G27, G29, G30, G31, G32, G33, G34, G35, G36, G37, G38, G39, G40, G41.

Upgrade your Glock’s internals with the ISMI Self-Defense Spring Kit, engineered for Gen 1–4 models. This premium kit is built from aerospace-grade chrome silicon alloy delivering superior reliability, smoother trigger operation, and consistent performance; ideal for defensive carry, high-stress environments, or high-volume shooting. Each spring is precision wound, heat treated, shot-peened, and stress-relieved giving you unmatched longevity and performance over standard wire springs. Whether you’re carrying daily or competing at a high level, this kit provides the control and durability your Glock demands. Get yours at NDZ Performance today!

Kit Includes:

• 6 lb. Extra Power Chrome Silicon Striker Spring, for stronger primer strikes.
• 6 lb. Extra Power Chrome Silicon Trigger Spring, reduces overall trigger pull weight.
• Reduced Power Chrome Silicon Firing Pin Safety Block Plunger Spring, smooths out the trigger break.

Features:

• Improves reliability in defensive setups and high-stress environments
• Reduces trigger pull weight when combined with a compatible 3.5 lb connector—potentially as low as 2.5–3.0 lbs
• Drop-in installation – no gunsmithing required
• Designed for both carry and competitive Glock shooters
• Made in the USA using aerospace-grade materials

Why Choose ISMI Premium Chrome Silicon Springs?

ISMI is a trusted name in Glock recoil systems—and now, their elite spring technology is available for your internal fire control components. Unlike standard music wire springs, ISMI Chrome Silicon Springs:

• Offer up to 10x the service life
• Maintain tighter tolerances under compression
• Provide consistent cycling performance over thousands of rounds
• Are heat treated, shot peened, and stress-relieved for superior durability
• Are built with the same technology used in IndyCar and Formula One racing, where precision and reliability are non-negotiable.

Perfect for:

• Glock owners wanting a smoother, lighter, more responsive trigger
• Concealed carry users demanding maximum reliability
• Competitive shooters needing consistency and endurance
• Anyone looking for a no-compromise spring upgrade

See our complete line of Glock Gen 1-4 Products here

Note: NDZ always recommends any part be installed by a qualified and trained gunsmith. NDZ promotes the use of safety practices and gear when working on any firearm.