When I tested the keyboard it worked perfectly and there is even an app for it.The sk61s are selling for around 60 pounds right now.The black optical switches make it more expensive but I think that the increase in price is better as the black optical are much better than the other types of linear switches. It also contains essential items like key cap pullers and switch pullers.They also contain extra key caps if needed but I haven’t touched them as they don’t look too useful for the product itself.It is only hotswappable with optical switches but the optical switches are all pretty good.I really recommend this keyboard for general use mabye not for hardcore gaming but it can be used for gaming.