What piece are you talking about specifically? If it's adaptive armour then any class can wear it. Whether they're light, medium or heavy armour wearers, hence "adaptive armour".
Weaspons that are BoL are different and can only be wielded by the classes that can wield those weapons such as Jedi and Sith classes with single blade lightsabers.
Plus the nice thing about BoL stuff is that you can take them off a character that's wearing it and send it back to another character cause it doesn't permanently bind itself to a single character in your legacy, you can swap it around as much as you want.