Wavelength: 635nm Size: 9 * 19cm / 3.54 * 7.48in(D * H) Precision: ±1mm/5m Model Number: E1303-1 Laser power:: < 5mW Operating Temperature:: -10 ~ 40°C Power Supply:: 3 * AA Alkaline Batteries(not included) Self-leveling time:: < 5s(magnetic damping) Brand Name: Seeedshed