Hi @vu.pham, I just had a pleasant discussion with @therese related to this product idea.
Since it’s hard to find the correct sub equipment, one possible solution is adding more filter criteria in the “Add sub equipment” panel.
Also, Therese has a very insightful example of how Redkon finds and links containers with shackles. I think you’re the best person to tell this example correctly, so could you please share the details here, @therese? 
I myself have an additional question regarding this topic:
After recent releases, Onix Inspect users can link main and sub equipment from this mobile application.
Here’s how it works:
- The inspector working on the field can hold the phone in his/her hand, open Onix Inspect and select the main equipment (for example, the container).
- Then he/she start linking, and scan the tags on many sub equipment one by one (the shackles, the slings, other loose gears).
- See the details here: How to manage main/sub equipment in Onix Work and mobile apps
Will this functionality (link equipment from Onix Inspect mobile app) help with your case @therese @redkon?