The MDF LUMiNiX II Illuminator Professional Diagnostic Penlight features a warm LED light for safe eye examination, a durable copper construction, pupil gauge reference and ruler, and a non-slip surface making this luxurious lighting instrument a leader in its class. 0.1 oz, 14.5cm long Batteries: 2AAA (not included) US Neurologicals is an official MDF dealer. Product IDMDF-61129