Are these cards guaranteed not fakes

I had no reason to think that they were fake. Worked very well. My Canon 5D cannot make full use of their 300m/b speed. I didn't know that at the time of purchase.

Will these work with a Lumix G7?

Yes, should work fine. The G7 takes SDHC & SDXC SD cards. I used these Lexar regularly on an Antarctic trip a couple of years ago, downloading cards used at the end of the day....took over 7000 JPG shots (also saved on card in RAW). They never missed a beat....often took burst shots of birds and whales up to 20 at a time!! They warmed up in the evening when transferring to back-up though!! Can recommend them!

Can this work with the canon m6 Mk ii please?

Yes, Canon M6 MkII support 1 x SD, SDHC, SDXC (UHS-II) memory card

Why is the write speed not stated clearly as its very concerning and a key fact.

How could any customers know why a manufacturer has done anything? If it’s ambiguous I think an intelligent person can work it why that might be. Sony Tough 300 / 299 far superior to this card. Yellow end goes into slot. Worth the extra expense imho.

Colour	Blue
Special feature	durability, high quality
Read speed	120 Megabytes Per Second
Item weight	8 Grams
Warranty type	Limited
Write speed	45.0
Hardware interface	SDXC, Secure Digital Card
Secure digital association speed class	Class 10
Manufacturer	‎Lexar Co., LTD
Package Dimensions	14 x 10 x 0.6 cm; 8 g
Item model number	LSD0800256G-BNNAG
Item Weight	8 g
Guaranteed software updates until	unknown

800x SD UHS-I Card

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