Reduce friction and increase the precision of your TRX-4M™ by replacing the stock bushings with these high-quality black-seal bearings. Black-seal bearings offer ultimate protection from the elements with less maintenance in dirty environments. Includes 3x6x2.5 mm bearings (8), 5x8x2.5 mm bearings (4), 4x8x3 mm bearings (4), 8x12x3.5 mm bearings (2), and 3.5x7x2.5 mm bearings (2).