Updating your sleeper lighting can make a noticeable difference with the 3 X 63 Inch Sleeper Extension Panels with 4 Amber/Amber M1 Millennium Lights, and its amber/clear lens variant, are stainless steel extension panels designed to fit Peterbilt sleepers up to 63?inches long, including models like 359, 377, 378, 379, 386, 388, and 389. Each pair of panels measures 3?inches in height and comes pre?equipped with four M1 Millennium LED lights (two per side) that provide amber illumination characteristic of classic marker lighting. Built from durable 304 stainless steel and finished for corrosion resistance, these panels are aftermarket replacements (not OEM) that include a manufacturer warranty against defects in workmanship and materials from the date of purchase. Verifying fitment for your specific Peterbilt model is recommended before installation to ensure proper placement and compatibility.