I was looking at a deal posted here for a free shower head and discovered that I didn't qualify due to where I lived. The site then offered me a Hansgrohe Croma Shower Head for 99p (free P&P) if I carried out an outline Water survey (what my head uses for water, appliances in the house etc. During the survey I was also given free;
ShowerSave – Regulate your shower flow to just 8 litres per
Tap Aerator Kit - twin pack of tap aerator inserts to convert two
kitchen or bathroom taps
Applicable for Severn Trent Water customer but I would check your postcode to see what else if available in your area.
The shower head on its own is a bargain.