I found these images in a Facebook group but the person who posted them did not know their origins and was trying to find more information.
Looking at the images below it looks like the circular button may be a safety. I think you hold it like a knife handle and your fingers wrap around the textured black portion. Then you would squeeze the black handle to fire the AOW.
If any of you readers knows more information about this interesting weapon, please comment below.
Edit: Thanks to our readers we have more info. It is a Llama Pressin pistol. It was produced from 1978-1995. It was chambered in 7.65×15. Made in Spain. Only 1000 units were produced.
You can find more information here.