Single slideToggle() for the same elements

I have this code HTML:

<div>
    <div>
        <button class="btn-slide"><span class="fa fa-caret-down" aria-hidden="true"></span></button>
    </div>
    <div class="block">
    ...
    </div>
</div>

And I have several such elements in my forum template. I use standard js toggle() script:

$(document).ready(function() {
    $('btn-slide').click(function() {
        $('.block').slideToggle(50);
    });
});

And when I click on button all components show or hide but I want to hide/show only this element which I choose. I thought that I can use $(this).childern in 3rd line but if you see .block isn't a btn-slide childern. So how can I achieve what I want?