Tell us about yourself!
For people who are interested in this collar - just the materials alone (not including the labor or the ID tube/tag you plan on using) will run you about $15-20 per collar unless you're buying in bulk, so you may want to just buy a cheap collar from the petstore unless you want to invest the time to make or pay up for someone else to make this.
Great design for outdoor cat - thanks for sharing. Why did you use stacks of 3 titanium rings - because your o-rings were too roomy without them? I am using 2.5 mm inner diameter o-rings and am using stacks of 2 titanium rings which I find to be sufficient and ultimately 50% lighter weight for my smaller than average cat. I wish you had specified the reason for the neoprene rings - I inadvertently bought a different material and didn't realize it would break down in the sunlight, so I have to start over :(