Hi I've been looking for other headphones with a longer jack and seen very few and reluctant to buy after the experience with the supplied headphones .
The supplied headphones are awful and just can't use anymore
I've tried the fospower adaptor and had to file down the adaptor around the end to get it to fit but it didn't last long .
It gave me the opportunity to try other headphones and found some didn't do well with the phone
My Apple headphones didn't sound right and Onkyo are a little better .I finally settled with cheap Samsung buds which worked well for me and the phone .
But unfortunately I can't get a good enough adaptor
For this rugged phone .really surprise blackview make a tough phone but it is badly let down by the headphones and Jack forcing the use of very few headphone .come on blackview how about a 90° headphone adaptor Jack that's fits snugly into the rubber cover on the top of the phone please .

Hi there! 
Please refer to this thread to get an adapter:
viewtopic.php?f=191&t=168899

It is about the BV8000 Pro, but the headphones' jack is the same