The RM09C is an LED sight powered by a standard CR2032 battery. Housed in rugged forged aluminum, it's extremely tough yet lightweight. The easy-to-use adjusters with audible clicks allow for quick windage and elevation adjustments. Featuring eight available brightness settings, the reticle can be manually adjusted by pressing the plus or minus buttons on either side of the unit. To switch to auto adjust mode, simply press both buttons simultaneously and release.