This broke straight out of the box on my initial weighing.  It spun back past zero to about 70 lbs the first time, and then back to 66 lbs the second.  So it now starts at -9 lbs.  It's totally unreliable for weighing bags -- well beyond the +- 2 lbs noted (but the tape measure may be accurate....).  It's a cheap piece of crap.

Don't bother purchasing this.  As someone noted, get a fish scale.