See Better Headband Hobby Magnifying Visor has many of the features of more expensive magnifiers.
The hands free hobby magnifying glass visor has two interchangeable magnifier plates, provide powers of 1.8x and2.3x. Used in conjunction with extra power lens (as illustrated) 3.7x and 4.8x can be achieved. Hands free visor magnifier. See-Better Headband Hobby Magnifying Visor Features.