Rollers come not only in different lengths, but in different girths. Don't get caught out by the different specifications: professional quality rollers and handles tend to have an internal diameter of 1 3/4 inches and the more DIY rollers and handles tend to have an internal diameter of 1 1/2 inches. The pro rollers are more expensive and take more paint so that professionals can work faster. They tend to have tougher, cage-style frames to make them more robust. One sort will absolutely not fit with the other. Do not worry though, we will always check when sending out that your goods are compatible.