It is a MUST, especially because theyre guaranteed to stay on your ear. I only bring this up all of this snobby criticism because Sennheiser is the company that created this product and because of its price of 199 gbp. Assembling the headphones is easy. In terms of sound quality, the drivers are well balanced and in harmony with PC or gaming console use. The hard part is you cant just reach and make an adjustment like you can on other headphone because they are touch sensitive. The headphones plug into the audio interface, which plugs into my laptop with a USB-C cable. I only wished Id bought them for him sooner - however he would only wear cheap, cheap sandals - which these arent. So, now I have one side damaged, the top damaged and a door damaged. First off, sizing. 5in separation after 2 months of wear between the rubber sole and the upper.