Building or rebuilding an AR-15 lower receiver? The Anderson Manufacturing G2K421A000OP lower parts kit delivers a complete, ready-to-install upgrade set in black—everything you need to finish your lower in one package. This kit is built around quality stainless steel internals, including a hammer and trigger that stand up to repeated use at the range or in the field. Whether you're assembling your first AR or swapping parts on an existing rifle, having all the small components organized and ready saves time and frustration.

What sets this kit apart is the attention to materials. The stainless steel hammer and trigger resist corrosion and wear, especially important if you're shooting in wet conditions or storing your rifle long-term. You get a complete A2-style pistol grip, all springs and detents, pins, and the trigger guard—nothing left out, nothing extra you don't need. Anderson Manufacturing has built a solid reputation for delivering dependable parts without the premium price tag of boutique brands, making this kit a practical choice for shooters who value reliability over brand hype.

This kit covers every internal component in the lower receiver, from the bolt catch assembly to the safety selector, hammer, and trigger group. It's the kind of all-in-one solution that works well for custom builds, replacements, or upgrading an existing lower. Since everything arrives as a matched set, you're less likely to end up with a stray pin or spring when you're elbow-deep in assembly.

Building or rebuilding an AR-15 lower receiver? The Anderson Manufacturing G2K421A000OP lower parts kit delivers a complete, ready-to-install upgrade set in black—everything you need to finish your lower in one package. This kit is built around quality stainless steel internals, including a hammer and trigger that stand up to repeated use at the range or in the field. Whether you're assembling your first AR or swapping parts on an existing rifle, having all the small components organized and ready saves time and frustration.

What sets this kit apart is the attention to materials. The stainless steel hammer and trigger resist corrosion and wear, especially important if you're shooting in wet conditions or storing your rifle long-term. You get a complete A2-style pistol grip, all springs and detents, pins, and the trigger guard—nothing left out, nothing extra you don't need. Anderson Manufacturing has built a solid reputation for delivering dependable parts without the premium price tag of boutique brands, making this kit a practical choice for shooters who value reliability over brand hype.

This kit covers every internal component in the lower receiver, from the bolt catch assembly to the safety selector, hammer, and trigger group. It's the kind of all-in-one solution that works well for custom builds, replacements, or upgrading an existing lower. Since everything arrives as a matched set, you're less likely to end up with a stray pin or spring when you're elbow-deep in assembly.