The cause of poor loading performance from the +2 range of Spectrums is often due to stretching and wear of the tape mechanism drive belt.
The old belts perished over time, particularly when stood unused for many years when they would often develop a "kink" where the belt rested unmoved over the capstan. This kink becomes a permanent feature in the belt causing it to jump when the drive is used again.
These replacement square section belts are to replace the large and small belts on the grey model Spectrum +2. They are made from modern, more resilient materials than the originals.
The small belt, only present on the grey +2 model tend to wear quite well and rarely need to be replaced, but if yours is worn and slipping then this is an ideal replacement to fit at the same time as the more troublesome large belt - both are included in this set.If you require just the large, main drive belt, these are available on their own.