image shows a Helix Oxford mathematical instruments set.

• The set is a 9-piece or 11-piece collection of mathematical tools, typically housed in a metal tin.

• It usually includes a compass, ruler, protractor, set squares, a stencil, an eraser, and a sharpener.

• The compass is a self-centering type with a safety point.

• The set is a well-known brand, particularly in the UK.