Square D ZB5AZ009 Body Fixing Collar Brand: Square D. Part Number: ZB5AZ009. Square D Body Fixing Collar, For Use With: Harmony XB5 Electrical Block, Plastic. Additional Description: SQD -ZB5AZ009 XB5A FIXING BASE. Catalog Description: Harmony, 22mm Push Button, XB5A operators, mounting collar for electrical blocks..