310777 SM Scales A16 Scales 1:1 /1:5/2.5, pair. Undrilled for fitting users own protractor head plates - aluminium/clear   310778   X10 Scales for SM 1:20/1:50, pair - clear perspex   310779   X10 Scales for SM 1:10/1:5, pair - clear perspex   310780   A10 Scales Metric/Imperial 1:1, pair - aluminium/white   310781   A10 Scales for SM 1:1 / 1:5/2.5, pair - aluminium/white