What is the weight of the rack hanging ?

I have not been able to find the weight of the specific rack, except for a number like

BRU61

Specifications Payload Capacity4 SDB class WeaponsWeight 330 lb empty(145 kg) 1,460 lb loaded (664 kg)Dimensions143” x 14” x 14” (363 cm x 36 cm x 36 cm)

https://webcache.googleusercontent.com/search?q=cache:q-obOBkoeqYJ:https://www.cobham.com/mission-systems/weapons-carriage-and-release/air-to-ground-weapons-carriage-and-release-systems/air-to-ground-bomb-racks/bru-61a-datasheet/+&cd=1&hl=vi&ct=clnk&gl=vn

What about BRU 55/57/67/68 ?