Most all of these scales are made in a couple of factories then bought and branded as whatever. China is making this stuff for pennies....
I have seen the exact same scale just with different printing on it from £6.99 in a cheap end hardware shop to £11.99 on fleabay to £39.99 in a local archery store.....they are meant to go to 80# but actually read to 100#  
I have 3 of the £6.99 ones and have been using the first one for over 4 years and it's still working perfectly.