Does anyone know what bulbs I can use to replace the PFKL518938 neo wedge bulbs in the heater control backlight on my 5th gen? The genuine ones are about £7 each & Lings want another £7 for postage

Not bothered about replacing them with anything colourful - just plain old stock will do fine (amber?), there are loads on ebay but not sure if I need the t3/t4/t5 & don't want to pull the controls out only to discover i've got the wrong ones - any help would be much appreciated!
Cheers!
John