Kev,
If you go for the Rega Adjustable Spacer, then you will have the option of running several different space amounts, and it is much easier to adjust/change, then by adding extra normal spacers.
If it is a stock 301 on a stock Rega table, then there should be no spacers from the factory on it.
Ortofon will suggest that you run either the 2mm or 4mm option on the spacers.
Hope this helps!
Rega and Ortofon dealer disclaimer********
If you go for the Rega Adjustable Spacer, then you will have the option of running several different space amounts, and it is much easier to adjust/change, then by adding extra normal spacers.
If it is a stock 301 on a stock Rega table, then there should be no spacers from the factory on it.
Ortofon will suggest that you run either the 2mm or 4mm option on the spacers.
Hope this helps!
Rega and Ortofon dealer disclaimer********