Winters Lm Mag Rear Endpackage Wink5270-A6 Includes The Following Options: #Win8133 Sprint Center / #Win8104 Posi-Lock Assembly / #Win8140 Aluminum Side Tubes / #Win8115 Aluminum Spool / #Win8137 Heavy Duty Gear Cover / #Win8143 Roller Bearing On Pinion Nose / Win8186P 6-Rib Machined Side Bells W/ Inspection Plug / 4.86 Ring And Pinion. Winters "Sprint Center" Quick Change Combines The Winters Spirnt Type Center Section With Closed Tube Bells To Make A Durable Yet Lightweight Setup For Standard Closed Tube Rear Ends. Every "Sprint Center" Rear End Is Built With 8104 Posi-Lock And 8143 Pinion Nose Bearing.