Square D (Schneider Electric) XVBC081 Stack Light. Schneider Electric Harmony™ Square D™ Replacement Cap Top Cover 70 mm Size For Use With: Harmony™ XVB Series XVBC2 XVBC3 XVBC4 XVBC5 XVBC9 Tower Light and Beacon Surface Mounting Black. Additional Description: SQD -XVBC081 REPLACEMENT CAP FOR XVB WIRING BASE. Catalog Description: Schneider ElectricREPLACEMENT CAP FOR XVB WIRING BASE70mmBlackDirectHarmonyHarmony XVBReplacement cap for XVB wiring basecovertop cover.