I'll apologise in advance for bringing up a topic I'm sure you've had before.
What models of mouse wheel are good? The 'classic' type with the bars are great for killing your mice and/or giving them nasty tail injuries, neither of which I desire for my animals while unsupervised.
I bought one which I thought looked good judging from online pictures, and it certainly was... although I looked at it and said it looked like it would rapidly wear out, which it did (many of you will be familiar with it, it's the one which says it's suitable for white mice on the box - perhaps it was my coloured ones which wore it out within a few short days).
The saucers are pretty cool, but they're also expensive, and I'm not willing to fork out $30 per wheel if they're only going to last me a few days or weeks. The last time I bought a saucer was over 15 years ago, and it lasted about a week. I have hundreds of mice, the enclosures are large and by most peoples' standards have a lot of animals in each (sometimes over 20), so these wheels will get almost constant use.
I could make my own saucer-type wheels which would not wear out quickly, but I'd need to use metal parts. Is there a reason the commercial models don't use metal? Is it simply that since it only needs to work for ten minutes to be sellable and metal would cost a few cents more, they just use garbage which will last a week or two?