Compatible With With The Following Vehicles:Compatible With: 1999-2000Compatible With Chevysilverado 1500,Ls,6 Cyl 4.3L,With Keyless Entry, With Power Windows1999-2000Compatible With Chevysilverado 1500,Base,6 Cyl 4.3L,With Keyless Entry, With Power Windows1999-2000Compatible With Chevysilverado 1500,Lt,6 Cyl 4.3L,With Keyless Entry, With Power Windows1999-2000Compatible With Chevysilverado 1500,Lt,8 Cyl 4.8L,With Keyless Entry, With Power Windows1999-2000Compatible With Chevysilverado 1500,Ls,8 Cyl 4.8L,With Keyless Entry, With Power Windows1999-2000Compatible With Chevysilverado 1500,Base,8 Cyl 4.8L,With Keyless Entry, With Power Windows1999-2000Compatible With Chevysilverado 1500,Base,8 Cyl 5.3L,With Keyless Entry, With Power WindowsProduct Info: Part: Door Lock Actuatorlocation: Front, Driver And Passenger Side Pair / Setnotes: With Keyless Entry; Intergrated Latch And Actuator Assemblyconfiguration: 3-Prong Blade Male Terminal; 1 Female ConnectorInterchange Part Number: 16637321, 16637320Additional Info: Silverado / Sierra Full Size Pickup 99-00 Door Lock Actuator, Front, Lh + Rh, AssemblyPremium Aftermarket Replacement Parts:Exact Fit To Original Equipment Manufacturer(Oem) Partall Of Our Items Are Dot And Sae CertifiedGuarantees And Warranties:30-Day Satisfaction Guarantee1-Year Limited WarrantyMade To Last: This Item Is Constructed With High Quality Material And Rigorously Tested To Ensure Structural Strength And IntegrityPlease Confirm Oem # Or Partslink # Matches Your Current Part Exactly Before Purchasing, Otherwise, The Item Might Not Fit. To Ensure Safe Delivery, Please Note Signature May Be Required For $200+ Orders.