it is fake or real transiator?

@terry9 thanks!  i conclude transistor have to buougt first and then  try with  spec   ,,, is there any way to detect without buy first?

Sometimes. As mentioned, the lettering is sometimes different. Also, pictures of the parts may indicate prior use or even hard use. Then there is cost - if it looks like an amazing bargain - maybe it isn’t such a bargain. You could ask the seller where the parts came from, and even ask him to prove it with a bill of sale.

I value my time enough to buy parts from a recognized and respected dealer, or even better, from the distributor. But I understand that not everyone can be so picky.

Whatever your situation, good luck!

oh yes , but it cost about an half from average person sell it ,, so i cant stand to buy it  ,,, i just wondering if any rare jfet could be faked to and hard to detect  ,, amyway thank you all for answer this yhread