Features: Dimensions - 100 x 100 x 25 mm. Stamp Size - 50 mm approx Stamp Dia - 33 mm Battery - 1600 MA / 1.2 volts Ni-Mh Solar Panel - Mono-Crystalline 2.4 V / 0.3 Watt. LEDS - 4 Nos. Super Bright (2 Nos. each side) Available Color - Red, Amber or White Weight of the Stud- 450 gms.(approx.) Working Time - 4 Days after fully charged battery. Advantage: