Field Magnifying Glass
Folding Field Magnifer
A normal magnifier has only one lens with a magnification of just 2 to 3 times.
A field magnifier or 'loupe' has 2 or 3 lenses (21mm diameter x 10mm apart) giving a magnification of up to 10x, essential for studying nature, coins, stamps, etc. In fact everythings looks cool 10x bigger.