I have 2 sets of Tru-Test Eziweigh and their load bars, I don't know about the 5i but mine would be the very basic model, I bought the first set but picked up the 2nd set at an auction pretty cheap a couple of years later and use the 2nd set around at my bull paddock, very convenient. I use mine on a platform in the race before the crush also, just different terminology. It would be 12 years since I bought the first set and apart from the internal batteries dying early in the piece they have performed flawlessly. I usually just clip them onto a small gelcell battery. They are basic and have to write the numbers down but are all that I need. I blame buying a set of scales getting me into this mess I am in now, once I started measuring I just had to keep improving so be warned it is addictive, I have been looking for a support group to help me with my habit but can't find one so I guess I'll just have to keep improving.
Ken