HDPE fresnel lens magnifier 

HDPE fresnel lens magnifier The Fresnel lens, simply say to be in the lens side have equi-distant tooth tattoo. Through these tooth tattoo, can achieve to specified spectrum light band tong (reflecting or refraction) role. The traditional grinding optical equipment band-pass optical filters are expensive. The Fresnel lens can greatly reduce costs. A typical example is PIR (passive infrared detector). PIR used widely in alarm. product model 8702-1 8702-2 8702-4 8708-4 8719 8727-1 8745-2 specification 44*149mm 38.7*104*0.6mm 23.6*65.5*0.6mm 32*66*76mm 34*53.5*0.6mm 18*37*0.7mm 37*74*0.5mm focal length 23mm 23mm 23mm / 22mm…