Today I purchased a four pack of tyre deflators. I went with Staun brand as I like the little leather pouch they come in. The Staun tyre deflators come set up at 18psi and are adjustable down to 6psi. I will stick to the 18psi, this should be a good start for my tyres. I also picked up a tyre pressure gauge to ensure the psi is correct. Looking forward to testing them out.