I can make them work. But...

So, I'm not sure what's going on with this. I bought 2, on the theory that they'd be an improvement over the existing timers that are leaking. I've encountered two problems with them thus far. Problem 1: The top does not correctly fit my standard hose-sized faucet. I can fix this by applying teflon tape, but... what? Problem 2: The aerator/water flow restrictor is so effective that water flow through the hose dwindled to almost nothing. I can fix this by removing the aerator, but then I get a loud squeal when I run the water. The timer itself is fine, and I can get around the problems, but I'm bewildered by what seem to be serious design flaws.

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