... 2.No blind spots 3.easy assemble 4.high quality Optical touch modules21.5 "Product SpecificationShenzhen Lianlilai Industrial Development Co., Ltd ... and dustproof, structural design, can also be resistance to light interference.4.Product composition is simple, easy assembly, maintenance easy; Users ... , Android2.3.6/4.0 7. Seven, structure size OTP Optical touch screen OTP