Philips
MASTER SON-T APIA Plus Xtra 400 Watt External Ignitor E40 (1950K) Philips SON-T APIA Plus Xtra 400W E40 1SL
£38.02
https://www.bltdirect.com/ Go to shop Description
It is Most-cost effective solution (both initial as well as running cost) in this category. 6 years service life. Highest lumen output maintained over life