Scalable Linear Recording is the name used by Tandberg Data for its line of QIC based tape drives.
The earliest SLR drive, the SLR1, has a capacity of 250 MB, while the latest drive, the SLR140, has a capacity of 70 GB. The term SLR is often used to refer to QIC tapes, as for many years they were the only drives that used them before Tandberg discontinued production around 2015.