Feildpiece RREF16 Reflectors (3) For SRPM2. The SRPM2 requires a reflection of itâ€™s laser to work. Proper use of reflective strips is critical to get accurate readings. To sense the reflected light, the reflective strip must be big enough, and you must be close enough. The Feildpiece RREF16 Reflectors (3) For SRPM2 are genuine replacement reflectors for this laser sensor.