6 Volts Base: European (E14) with Special Flange (P44s) 360 lumens Maximum Overall Length: 2.52 in Average Life: 100 hours The 366 6-Volt Slit Lamp bulb- equivalent is used in the Haag-Streit Models BA-904, BM-900, BP-900, BQ-900, BX-900, and Model 900 (Non-Halogen).