The Osram 64634 HLX is a 150W 15V MR16 lamp with a GZ6.35 base, Primary Applications: Microscope, Scientific, Medical, and Dental Applications ANSI EFR Product features  • Xenon instead of krypton as the filler gas (XENOPHOT HLX versions) • Luminous flux up to 10 % higher with same power consumption (XENOPHOT HLX versions)

Osram 64634 (EFR) Specifications:( Replaces Philips 6423 15v 150w) - Mfg. Ordering Code: 54210 - ANSI Code: EFR - Wattage: 150 Watt  - Voltage: 15 Volt  - Bulb Base: GZ6.35  - Shape: MR16 Reflector  - Type: Halogen with Reflector - Type of Current: AC  - Working Distance: 1.260(in)  - Working Distance: 32(mm)  - Average Life Hours: 50 Hours