I was going to buy a Koul tool set originally, until I saw that it doesn't work w/ the PTFE-lined hose setup. Then I saw about an equal number of people saying their PTFE fittings installed w/o issue vs those saying they weren't able to get 'em in and/or they were a major PITA. I was still good w/ the idea of the hose upgrade, so my solution was to measure the original rubber hoses lengths and buy two pre-assembled PTFE-type hoses in the next length up from them.