Test Jars are necessary to take readings from the hydrometer since testing should never be performed in a bottle.
They have to be tall enough to allow the hydrometer to submerge properly into the alcohol being tested. The small diameter keeps the hydrometer from tipping over and minimizes the amount of product that needs to be tested. The straight clear sides allow the hydrometer numbers to be easily viewed so you can obtain an accurate reading.
Don't be fooled by very low priced hydrometers or test jars you find advertised on the internet. Those are cheaply manufactured and will not provide the accuracy or longevity that our products will provide. You get what you pay for. Our hydrometers and test jars are top-of-the-line quality and every purchase is backed by our
30-day Satisfaction Guarantee.