Ebay trimpot kits

[microbug]

I don't have any sets of trimpots and I'm looking for a comprehensive set. On eBay, there are several kits from China (search used is here, I was thinking about the 130-piece kit about half way down the page (here).
Does anyone have any experience with these? Two of the kits claim to be Panasonic - could they be surplus or just fakes? These are trimpots, they will probably only be adjusted a few times - what can go wrong with cheap trimpots?
Thanks!

[apelly]

Got some similar a while ago. Fake no doubt, but OK for prototyping. Wouldn't dream of using them for anything important.

[microbug]

OK. I might get a set and when I finish a project put genuine trimpots in. At about 9p each in large quanties (100+), it would be possible for the panasonic ones to be genuine, but unfortunately it's unlikely. I was also considering the skeleton trimmer kit from Bitsbox, which I'm sure would be reliable, but I don't like the idea of exposed carbon tracks - how much do this type of trimpot drift over time?

[nctnico]

I'd get genuine trimpots especially for a prototype. If you encounter a bad one you'll be looking for the error for a long time.

Don't put too many trimpots in a project  One of my former bosses never took care to calculate values and just used trimpots. Some products contained over 20 trimpots and a thick manual on how to adjust them properly. But in the end only he could get the product properly adjusted.

[microbug]

OK, I'll go for the Bitsbox set then. I'm only using one trimpot to precisely set the minimum output of my project (LM317 power supply) to 0v, but I'll keep that in mind in future! My old Hitachi 'scope has at least 30 trimpots and quite a few trimmer caps as well!