Professional quality triangular scales are 6 sided with 12 sets of ratios. The three models cover most professional and student needs.

Ratios included are:

#402 - 1 ;100, 20, 250, 300, 400, 500.
#403 - 1:20, 25, 50, 75, 100, 125.
#409 - 1 ;25, 5, 10, 20, 50, 100.

Kent Adjustable Set Squares are a professional grade instrument that features a clear transparent surface and a precision divider in degrees. The Kent Adjustable Set Square also features bevelled edges for ink pens/markers and an easy-to-alter arm.

Quality oval scale rule with precise division ratios on both sides, 30cm.
Different models to suit various technical requirements.

#61M - 1:1, 2,5,10.
#62M - 1:1, 5, 10, 100, 20, 200, 50, 500.
#63m - 1:1, 10, 20, 200, 25, 250, 50, 500.