Hello @Ljb1 hope your having a good day.
I've gone through a few of the cheep ones.
So I switched to Blue Planet for my pen.
It was a bit more money but it works well and is long lasting and reliable.
Give one a try, worth the money.
I have an Apera and a cheapo....the cheapo has always been in range of the Apera, just make sure you calibrate the cheapo from time to time. But Blue Lab, Apera are 2 of the more known pens.
I've gone through a few of the cheep ones.
So I switched to Blue Planet for my pen.
It was a bit more money but it works well and is long lasting and reliable.
Give one a try, worth the money.
Stay safe
Bill