I bought one of those for my XL years ago, only it was red. I thought it would be a performance upgrade because it touted an improved advance curve, plus I was suspicious of my original. I noticed no difference between it and stock, other than it was smaller and didn't fit the holder as well.
Apparently it was reliable since I have done over 20,000 miles with it. I quit carrying my stock one as a spare long ago. I bought mine off eBay from an unknown source. I agree your find looks legitimate in the fact that they have a variety of items all related to electronics. The price is cheap enough to use it as a diagnostic piece.
I often weigh purchases in the shop that way. Sure it is throwing parts at something but the diagnostic time in chargeable hours adds up quick. If it works you are done and can move on to something else, if not, you gain valuable knowledge fairly cheaply as opposed to hours wasted.