Most Keurigs use the same K Cups as long as the Keurig you have says it takes the K Cup and not the K Cup Pods.
If your Keurig machine takes the K Cup Pods then the regular K Cups will not fit and you will have to use the K Cup non pod type.
However Keurig machines will only accept K Cups that are made from the same manufacture as them and you cannot buy other K Cups to Fit in a Keurig machine.
So if you have a Keurig machine you must use the K Cups from Keurig or they won't fit.