Need to replenish my stocks, but confused to find I can get 2 pin in 16 or 28W, and 4 pin in 16/21/28/38/55 watt.
Am I right in thinking there just two physical sizes: 2 pin about 14 cm across and 4 pin about 20 cm across, or are there maybe more sizes? Don't want to order 38s only to find they won't fit in my light fittings.