Description
FOR AIRSOFT USE ONLY!
ESD ER-15 GBB original parts.
Compatible with VFC M4 /HK416D GBB series.
Please notice the corresponding installation information below.
● Product Brand : ESD (TAIWAN)
● Material : Steel

※ Requires DIY skills.
※ Cross-brand installation may involve slight tolerances or size differences — please adjust or grind as needed according to actual fitting.
※ Designed for installation on VFC M4 V2 / HK416D Gen2 GBB series — converts split valve knocker parts into an integrated component.
※ For the latest VFC M4 V3 / HK416D Gen3 GBB series, it is recommended to use the original VFC V3 valve knocker parts to ensure optimal fit and performance.
Compatibility:
✓ Compatible with VFC M4 V2 GBB series ✓ Compatible with VFC M4 V3 GBB series
✓ Compatible with VFC / Umarex HK416D Gen2 (V2) GBB series
✓ Compatible with VFC / Umarex HK416D Gen3 (V3) GBB series
✗ NOT compatible with VFC KAC SR-16 E3 (V2 system) GBB series (Ambidextrous Bolt Catch)
✗ NOT compatible with VFC / Umarex HK416A5 GBB (Gen2 or Gen3) series (Ambidextrous Bolt Catch)