I am looking for an alternative to this keyboard:
https://www.amazon.com/dp/B00H88HC4Y
The most important thing about this keyboard is its size and shape. An alternative cannot be any bigger. Smaller keyboards than this one are fine.
The keyboard has to roughly fit the long side of a phone.
More keyboards resembling what I am looking for:
https://d2pa5gi5n2e1an.cloudfront.net/webp/ph/images/article/1204/image-3.jpg
What about his Bluetooth device :
It’s about 20 cm wide.. bought it on e-bay 4 years ago (rechargeable over USB) - labelled as :
“Wireless Bluetooth Keyboard w/ Touchpad For All 7-10 inch Android Tablet”
But I’ve never used it with Android, I used it on a few Single Board Computers like BananaPi and NTC CHIP…
Unfortunately, it is way too wide. If I could just imagine one and pop it into existence it would be about 6cm wide. 
Due to the low amount of keyboards I found that are extremely small, I would be fine with one being maybe 10cm wide. But that should be the absolute max. Else it does not work for the purpose I want to use it for, in the first place.
What I don’t really understand is, that there are so many Blackberrys and similar phones, that have an attached irremovable keyboard that is always super tiny. However finding an unattached keyboard you can attach somewhere yourself of this size, is like trying to find a needle in the hay stack. So far I only found 2 keyboards that are at least close to the size I need, but both aren’t really good and it wouldn’t be so great if I really had to resort to them.
Wouldn’t it be easier to just use a stylus? I find even normal size keyboards have the keys too close together and using screen keyboard on phone is exercise in frustration. I bought a keyboard/cover for 10" tablet but couldn’t use it although my wife thought it was great (she has much smaller hands than me)
I took phones as an examples, to easier imagine what I need, however I don’t need it for a phone. Additionally, touchscreens are always slower to operate (definitely for me) than hardware keyboards. If that wasn’t enough, the touchscreen I will be using has about 2FPS, so typing through that would be even slower. The screen is also only 3.5" in diameter, so using an on-screen keyboard would cover the whole screen.
That’s why I actually need a hardware keyboard.
