This is how you post a link on the forum.
And did you notice that I have not quoted your entire last post in my post? Please only quote relevant sections of other posts when you need to. Otherwise use Reply.
The picture clearly shows a resistor inside the shrink tubing. Not something cleverer like a constant-current circuit.
The eBay page says voltage between 5V and 12V and current between 15mA and 20mA. This is impossible.
At 12V, to achieve 20mA current, the resistor would need to be around (12-2)/0.02 = 500R
But at 5V, the current would be (5-2)/500 = 0.006A = 6mA, not 15mA
So on the basis that the supplier is promising something impossible, I would not purchase. Fortunately for the supplier, I guess lots of his customers don't know Ohm's Law.
The supplier also says these leds are suitable for use with Raspberry Pi, which is a 3.3V device, so not in range 5V to 12V...