This is the English edition of a review from my Japanese YouTube channel, iestaLife. I review gadgets from my home studio in Japan, so product links go to Amazon Japan.
Quick take
The CASEFINITE THE FROST AIR ULTRA MAGNETIC is not the lightest ultra-thin case for the iPhone 17 Pro Max, but it is the one that still feels like a real case. At 24.7 g on my scale it is about 10 g heavier than the flimsiest option I tried, and that extra weight buys a frame that does not warp.
What I tested
- CASEFINITE THE FROST AIR ULTRA MAGNETIC for iPhone 17 Pro Max, in Smoke Black (Ice White is also available)
- For comparison: an ultra-thin memumi case and a PITAKA aramid-fibre case, both for the 17 Pro Max
- A MagSafe strength check, MagSafe charging, and a pull test with a double-sided MagSafe ring on a car mount
What I found
- Weight: 24.7 g for the Frost Air Ultra, 13.5 g for the memumi and 20.6 g for the PITAKA (I misspoke as 24.6 g in the video; an on-screen note corrects it).
- The memumi is astonishingly light, but it had already bent out of shape after being fitted only a few times. The Frost Air Ultra feels noticeably stiffer.
- The matte coating is smooth yet grippy, and it barely picked up fingerprints.
- The buttons are open cut-outs, but the case is so thin that pressing them and using Camera Control was easy.
- The smoky translucent black lets the orange iPhone show through, which looks better than I expected.
- MagSafe hold is strong: the phone stayed put when I shook it, and MagSafe charging works.
- The camera surround is raised, and the front lip sits just slightly above my glass screen protector, so the screen should not touch a table when placed face-down. It is close, though.
Weight comparison
| CASEFINITE Frost Air Ultra | memumi ultra-thin case | PITAKA aramid case | |
|---|---|---|---|
| Product |  |  | |
| Weight (measured) | 24.7 g | 13.5 g | 20.6 g |
| Feel | Stiff, holds its shape | Lightest, but warped after a few fittings | Light and well designed, open cut-out |
Who it’s for
- People who want their Pro Max to stay as slim as possible
- Fans of ultra-thin cases who found cheaper ones too flimsy
- Not for you if you want drop protection on hard surfaces like asphalt
- Not ideal if you snap a double-sided MagSafe ring on and off a car mount all day
Watch the review
The video is in Japanese. The weight comparison starts around 2:20, and the car-mount pull test around 7:25.
Limitations
I did not drop-test the case, so I can’t tell you how it survives a fall onto concrete. In my double-sided ring test, the ring stayed on the car mount rather than the case unless I held the phone down while pulling it away; only two of the 20-plus cases I own (Peak Design and Aulumu A17) pass that test. Prices mentioned in the video were Amazon Japan’s at the time of recording (list price about ¥6,500, then ¥5,600).
Products
CASEFINITE THE FROST AIR ULTRA MAGNETIC (Smoke Black, iPhone 17 Pro Max): on Amazon Japan
The Amazon Japan link above is an affiliate link. As an Amazon Associate, I earn from qualifying purchases. Check the listing for the exact model, current price and shipping availability in your region.
More reviews in English
All Cases (56) →Browse all English reviews →
This review is also available in Japanese.