The 556 is an XS Power battery installation accessory. XS Power lists it as: I-BAR Multi Top Post Terminal Adaptor - Top Only. 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 556 I-BAR Multi Top Post Terminal Adaptor - Top OnlySpecifications Model 556 Product Type Terminals, Hardware & Hold-Downs Warranty 1 year UPC 692209014645 Package Length 3.75 in. Package Width 2.25 in. Package Height 5.75 in. Package Weight 2 lbs. 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.