This is a unique product by ProSolve that has been specifically designed to powerfully inject compressed air into blocked sinks to effectively remove common blockages quickly without any mess or hassle.
This is far more powerful than manual pumps (that I personally find difficult to use anyway), or one of those flexible wire unblockers that just bring grease and debris back into the sink!
The 200ml can provides 20 good one second applications.
B&Q stock a similar product called “Power Plumber – 150ml” – which is priced at £16.00 per can (Price correct as of 01/03/2018).
It does not pollute, it has no corrosive chemicals, it keeps everything clean and simple.