QSA 1" / 2" Adjustable Rear Lowering Drop Shackles Compatible with 1988-2018 OBS, NBS and NNBS GMC Sierra 1500 (w/OEM Style No-Squeak Bushings) Includes 1 set of 1" / 2" Adjustable Lowering Shackles (L+R) Shackles come with Ultra High Quality (OEM Style) Rubber Encased SILENT Bushings. These Bushings Do NOT Squeak and Don't Require Greasing. Heavy Duty Black Powder Coating Gives Excellent Appearance and Protection from Rust! Fits 1988 - 2018 GMC Sierra 1500 Do Not Buy Shackles with Cheap Bushings or ones that require Greasing. These only cause more work for you and they end up squeaking anyways. Go with the only true solution. OEM style Rubber Encased Bushings will give you the quality you need in a bushing.