I believe it's rated for 72 oz., which would make it 4.5 lb. Not a big deal, since I mostly make 1 lb. batches anyway (although I'm thinking of switching to 2 lb. batches to help improve lye accuracy, and use TOMATO JUICE! )
I just used this scale for batch #7 and we'll see how it works out. It displays up to 2 decimal places for the weight measurement, and it "feels" pretty accurate.
It should be fine until you start making larger batches, 2 decimal places is good (the 100th place)... I like to weigh with these smaller scales in grams because its more accurate that way IMO, and I like working in grams because I can do the conversions a little easier...but thats just me, everyone develops their own way
A nifty tip I read before I started was to cover your scale with plastic wrap.
I take a piece and lightly lay it over the scale covering the buttons too. Then when I am done, toss it in the trash. It keeps the buttons clean and has protected the scale from spills and dribbles many times.
I change the plastic wrap after weighing lye (I do this outside) before bringing it back inside. I spilled some FO once and waited until I was completely finished with soaping and clean up to remove the plastic. It had melted onto the plate from the FO. I keep a paper towel nearby to blot in case I spill, but remove now it if it is something I think will eat it.