Holographic diffraction grating for teaching 1.3 usd/pc 600 lines 300 lines 100 lines 50 lines in china

meillä on paras holografisen diffraktiohilan valmistus Kiinassa

600 lines 300 lines 100 lines 50 lines for 1.3usd/pc

the size is 36mm x 38mm

$Holographic diffraction grating for teaching 1.3 usd/pc 600 lines 300 lines 100 lines 50 lines in china-MasterLi, Kiinan tehdas, toimittaja, valmistaja$