Material: the scale ruler set is made from durable metal brass, durable, lightweight and reliable. Very sturdy, hard to bend the rulers and dont easy to destroy the shape, can be use long time. Easy to Measure: 4 inch/ 10.1 cm 180 degree protractor, 30/60triangular ruler, 12cm straight ruler, make it convenient to get the angles' degrees, measure and drawing. Lightweight, can easily be put into your school bag. High Visibility: Quick and easy to read. Sharp graduations and precise markings perform well on any surface. Preventing unnecessary eye strain. Wear-resistant, don't fade. Golden betiful look and simple, fine workmanship. Used for any occasion, such as life, study, work, experiment, stationery, bookmark ,home decoration etc. Ideal gift for your kids, friends and students. With reliable construction and accurate performance. This geometry set is perfect for architects, engineers, draftsmen, builders, artists, designers, roofers, teachers and students, etc.