Don't cheap out...
The fellow I subcontracted to wanted to purchase "value" hydrometers for his battery customers. He purchased a carton of 96 "EZ RED" hydrometers. I titrated a batch of 1.250 new electrolyte for a test base. Twenty or so hydrometers later, the box was resealed and on its way back to the vendor. "How can they sell******like this?" was his key remark. Floating balls? Try anywhere from three to five with four being correct. I won't even bother telling you about the ones that leaked.
Automobile parts store hydrometers can be just as ridiculously erroneous. You wouldn't put up with an oil pressure gauge that read 80 PSI when in truth pressure was 6 lbs, so why put up with garbage readings on a hydrometer?
The Freas is EASY TO READ. The only trick is to rinse it out thoroughly with clear water after each use. Squeeze the bulb, fill the tube, tilt the hydrometer back and slosh out the rubber bulb, the expel the water. Do this a couple of times. Acid is what makes bulb and fittings rubber eventually get cracks.
Large diameter black PVC pipe sold in Hardware stores makes a great hydrometer container. Cut to length. Seal one end with a cap. Use an adapter sleeve with threads on the other end. Screw in a threaded cap, the one with the square tip sticking out to grab and spin with the fingers. The rubber parts of the hydrometer will protect it against bumps. The big PVC tubing is thick. You can drop a hammer on it and not hurt the hydrometer inside.