The following 8.5 kW showers are the most suitable retro-fit replacement models:
Stanza 8.5 white*
The showers below could also be fitted although there may need to be some alterations to the pipework and wiring:
8.5 se - with a gloss white finish
8.5 cse - with a satin chrome finish
8.5 gse - with a stylish graphite finish