This bearing block LWES15Q is suitable for select Roland printers (see compatibility list below). This part includes the blocks only (without the rail) that corresponds to Roland part number 21895169. This is the full block with the ball bearings mounted in. When your printer has an SSR15 linear bearing with SSR15 blocks, please refer to spare part PMERO17737, PMERO17713 or PMERO17563.
When your printer is equipped with the older, discontinued LWES15Q linear bearing with LWES15QQ bearing blocks, you need to replace the entire assembly (see spare parts PMERO13867, PMERO7915, PMERO22564), the rail only PBRRO82357 is available for Roland XJ-640 printers.