Wireless, battery-powered sensor

A sensor comprising:

• a sensor module comprising an electronics board and a battery enclosure, wherein the electronics board is coupled with the battery enclosure, and wherein the electronics board comprises a sensing component;
• and
• a sensor cover comprising:
• a housing comprising an inner surface defining sensor module receiving area, wherein the sensor module is received within the sensor module receiving area, and wherein the housing defines an optic aperture and a button aperture;
• an optic supported on the housing and extending at least partially through the optic aperture;
• and
• an optic retainer wherein the optic retainer comprises a base and at least one post extending from the base,
• wherein the base of the optic retainer comprises a button that is positionable within the button aperture and movable relative to the base such that the button selectively engages the sensor module,
• wherein the optic retainer is positionable within the sensor module receiving area such that the base engages the optic, at least a portion of the optic is retained between the base and the inner surface of the housing, and the at least one post engages the sensor module.