The other person said heat dissipator. The usual phrasing is heatsink. Your nvme is gonna have a four digit code like 2280 following the m2 designation. The last two digits indicate the length. If you cannot see the code or look up the product description then you can measure it. If you can’t measure it then you can instead look at the supported nvme form factor documentation for your case and ensure it meets the 2280 constraints. 2280 is the biggest m2 nvme ssd size so if your case supports it you’ll be fine. Make sure it’ll work by looking first, but five bucks will get you a passive heatsink that will probably keep you in good stead over five minute transfers and twenty bucks will get you one with a little fan on it that will make sure you’re golden even during extended transfers. Post the case model and I’ll look up what will fit in it with links and also see if there’s a good spot to sneak a fan in.