
I have a matetel and i think it is very good, but must be used correctly, you really need to collect a watery sample not a slobbery sample, i couldnt use it on my ddb as she is too slimey!
used it on my rotts twice and results were very clear when to mate, both matings produced litters of 9 and 12!
The best way to get a watery sample is the get your girl drooling over a juicy treat or after she has been excercised and is panting, i just caught the drip straight onto the lense, if watery 1 drip will be more than enough, when you get the correct time the ferning is VERY clear!
you want the lense to look like a frosted window and you should see this develop over a few days
good luck