This is actually a pretty neat product. The travel squeeze tube has a rollerball applicator that you roll on the under eye area, squeezing slightly to dispense the product. The rollerball is metal so it always apply cool. However, it applies a tad too cool, cold almost, which makes me think there are plenty of alcohol in it, which is kind of iffy since it's for delicate under eye area.
The serum itself is a viscous clear liquid not unlike Japanese lotion (toner). It took a few minutes to absorb in the hot and humid environment I was in but it did absorb completely. I found it adequately moisturizing for daytime use and the light texture was perfect with the weather. If I were going to Japan or Taiwan again I'd definitely pack this along! Since I used it for only several days, I'll probably give it another try later down the road when it gets warmer in SF.