Upper Parts Kit (UPK) for Glock 19 Gen 4. These are great for completing your custom slide. All parts are from US manufacturer. All Parts are made to the highest tolerance to the original specification. Warning: This product is to be installed by a competent gunsmith. No liability is expressed or implied for damage or injury which may result from installation or use of this product. DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols. Specifications for Zaffiri Precision Glock 19 Gen 4 Upper Parts Kit: Manufacturer: Zaffiri Precision Fabric/Material: Metal/Plastic Gun Make: Glock Gun Model: Glock 19 Gen 4 Model Generation: 4 Package Contents: Zaffiri Precision Glock 19 Gen 4 Upper Parts Kit Firing Pin Spring Firing Pin Spacer Sleeve Spring Cups (2-Pack) Firing Pin Safety Nitride Firing Pin Safety Spring Extractor Depressor Plunger Nitride Extractor Depressor Plunger Spring Spring Loaded Bearing Firing Pin Channel Liner Extractor Slide Cover Plate Aluminum Recoil Sring Assembly