This product is the equivalent of a 10 weight, non-detergent lubricating oil. For my HVAC system's air handler motor (drives the squirrel cage fan) which has a tiny port with which to insert drops of oil, this oil or nothing heavier than #20,non-detergent, is the best. FYI, 3-in-One makes something touted as suitable, but it is probably less suitable for electric motor bearings, & ditto for WD-40 brand products, according to HVAC maintenance websites and product maintenance literature. I've read there to never use oil with detergent in it for electric motors, and stick to 10 or 20 weight. From what I've been able to find, this little zoom oiler is the right item.
The zoom spout oiler's tube is longer than it looks - you can pull it out, that's why it's called zoom oiler. That's what you need to get it into tight spots. And the average tinkerer or home consumer doesn't need more than 1 or two of these little oilers, so vendor sites online elsewhere are often less suitable because they only sell in lots of 6 or 12 or more.
Regarding the 1st reviewer having hard time finding marketplace vendors who are reliable: Yes I found it very hard to find from dealer with a proven customer satisfaction history. It's hard to find for reasonable ship cost... the item is small and worth 1-3$ individually. But some vendors everywhere routinely tack on a 7-10$ ship cost which is 2 or 3x what they should charge - IMHO, should be comparable with buying a book on amazon marketplace which weighs more.
Per the MSDS product specs sheet, this item is made by Phillips 66 company in CA; the website shows who distributes. Easiest is to get it here through Amazon marketplace via Ace hardware (good customer satisfaction ratings), or your local Ace if you have one close enough. If the item isn't available when you need it in a hurry, check your local hardware stores; if all else fails, you can get it at hvactool for one or two, or for several, go to bluelakeproducts. But look here first!

I ordered 2 of: NORVEY INC ZS75A "ZOOM-SPOUT" LUBRICATING OIL (PACK OF 12), but only received two ZOOM-SPOUTS. I attempted to contact the seller, McLendon Hardware, by email, but I never got any response. I got curious and checked the seller's reputation and unfortunately they've done this before.