The 587 is an XS Power battery installation accessory. XS Power lists it as: M6 to 3/8" Stud Adaptors, Zinc Plated Hardened Steel. The specifications below come directly from XS Power's June 2026 distributor data. Verify voltage, group size, polarity, dimensions, and application requirements before ordering.This Listing Includes: (1) XS Power 587 M6 to 3/8" Stud Adaptors, Zinc Plated Hardened SteelSpecifications Model 587 Product Type Terminals, Hardware & Hold-Downs Warranty 1 year UPC 692209015482 Package Length 3 in. Package Width 4 in. Package Height 1 in. Package Weight 1 lb. Available from JS Alternators.PROP 65 WARNING: This product can expose you to chemicals including lead and lead compounds, which are known to the State of California to cause cancer or birth defects or other reproductive harm. Wash hands after handling.For more information, visit www.P65Warnings.ca.gov.