Ideal for clamping onto work surfaces up to 1" thick. Provides your craft with magnification right where you need it! Rimless lens gives a comfortable uninterrupted view (7" flexiarm). Available in black and three fun, bright colors! Main Lens: 3½" diameter, 2.25x magnification (5-diopter). Insert Lens: ¾" diameter, 4.0x magnification (12-diopter).