OTR Wheel Engineering Canadian division has excess inventory of 57" Lock Rings used on large EM 57" wheels. Our part number is LR57HD. Cross Reference Part Numbers are: 534745700, LR57HD84, LR57EU. The LR57HD lock ring is a Phase I design which is the industry standard for 51” and 57” lock rings. Fits Rim Sizes with Phase I lock ring groove: 57 x 27, 57 x 29, 57 x 32, 57 x 34, 57 x 42, 57 x 44, 57 x 47, 57 x 52. Other OEM part numbers for the LR57HD would be: Caterpillar® PN: 8W0335. Cat list price is $552 plus freight. Euclid: E4084466 Komatsu: AK8013 LeTourneau: 4093793 Kress: 064482, 104672 Terex/Unit Rig: 22777 Topy: LR57EU www.otrwheel.com