BS 3541:1962

Totally enclosed fittings for general examination and minor surgical purposes; fittings for special purposes such as ophthalmic lamps and operating theatre fittings not included. ¶ For operation at lamp voltage up to 25 V either by connection to transformer or direct connection to 25 V a.c or d.c. supply. Two types, one giving concentrated beam for minor surgical procedures, the other a larger illuminated area for general examination.