How do I stop cats coming into the garden

The device is "Pestbye" not sure if I'm allowed to say the company but if you google

"Sonic Cat Scarers" click on images you will see it at £14.99 plus £4.99 postage .

Have a read of the reviews there quite good.
Im tempted myself to get one.

Absolutely nothing works to deter cats don’t waste your money
I ve tried the high sound sonic thingy I took a picture of the cat with its bum an inch from it and got my money back
Lemonade bottles filled with water
Anti Cat pellets
Orange/lemon/grape fruit peelings
Curry powder
Pepper
Little things stuck in the ground and smell of citrus
Silver things twiddling in the wind
Prickly branches
Short of a bucket of water (which means I ve got to sit in wait 24 hours) I m out of ideas but don’t waste your money on expensive things

I started a thread on this a few weeks back when my bulbs were constantly getting scratched up

The videos of the Water Cat Scarer look pretty ok, but means you have to have it hooked up to your hose all the time,but a couple of times and the cats wouldn't want to risk coming back.

I think that might actually be the one thing that may work Bikergran but I don’t have an outside tap (foiled again )

hmm (thinking emoji)