Pack of 5 Fluorescent Tubes T5 525mm 21 inches Cool White 4000k 13W : Amazon.co.uk
13W Fluorescent Tube-5-413-20
Fluorescent-lamp formats - Wikipedia
Philips High Frequency 5' 50W 840 Cool White
Buy ETERNA N64/5 16W Triphosphor Fluorescent Tube from £6.19
5 Foot T5 Fluorescent Tube 49W G5 4000K Cool White - John Cribb & Sons Ltd, UK Electrical Distributors, Dorset, Hampshire, Wiltshire, Somerset & the Isle of Wight.
GE 5' 58W Colour 835 White – The Lamp Company
Osram 35 W T5 Fluorescent Tube, 3300 lm, 1450mm, G5