美国采购需求：游标卡尺、左手游标卡尺、数显卡尺、带表内径表、带表卡尺、外径千分尺

I've recently purchased 6 digital calipers with an IP54 rating from Amazon, but unfortunately, I've encountered several issues. One of the units is missing a screw for the battery cover, and the measurement indicator shows feet as inches. Additionally, the adjustment wheel doesn't function properly. I expected a premium product given the price, but this has been a major letdown. Returning for repairs is a hassle I didn't anticipate and involves unnecessary time and cost. I'm requesting a no-cost replacement for the faulty units. I've already paid for these items once, so I hope you can expedite a solution to this issue. Thanks for your attention.