Genuine Replacement Welch-Allyn lamp Features Features exclusive curved filament, specifically designed for Welch Allyn’s hole-in-the-mirror ophthalmoscope design The 04900 lamp fits Welch Allyn 3.5V ophthalmoscope models Nos. 11720, 11730, 11735, 11620, or 11630 High energy efficiency, resulting in 3X the examination time with each charge of a Welch Allyn rechargeable handle