ABS and transparent and acrylic. Liquid filled. Each on a blister card. Red LED light with on-off switch. Side ruler. Magnifying glass. Made of aluminum. Compass is made by PVC, magnetic material, white mineral oils. Uses one lithium battery, style CR2025 (included). A great device to determine geographic direction. Ideal for camping, hiking, boaters, emergency supply, boys scouts, etc. 17 x 5.9 x 2.1 centimeters aluminum cast case, pp glass.