A occupancy sensor having a replaceable cover with a convenient adjustment and installation scheme is disclosed herein. More particularly, a single or multi-technology occupancy sensor, assembled inside a semi-spherical shaped enclosure includes a replaceable cover with a convenient adjustment and installation scheme. This sensor design enables the sensor to be rotate after installation to obtain a desired coverage patterns. Specifically, the housing for the occupancy sensor includes a front cover having a lens assembly, a base assembly, a harmonic wheel, and a back cover. The front cover couples to the base assembly such that tool-less, manual access is available through the manually removable cover assembly to adjust several features of the sensor. The harmonic wheel enables the front cover, which includes the lens to swivel from zero to 359 degrees relative to the back cover anytime after installation.