A spec sheet tells a shopper what a thing is. A good description tells them what it will do for them. Most stores stop at the first, and wonder why the page does not convert.
Lead with the outcome
Open with the change the product makes in someone's day, not its dimensions. The dimensions still matter — they just belong a little lower, once you have given the reader a reason to keep reading.
Answer the question they are already asking
Every product has one nagging doubt attached to it: will it fit, will it last, will it work for me. Name that doubt in the copy and put it to rest. A description that pre-empts the return is worth more than one that just sounds nice.
Write like a person
Read it aloud. If you would not say it to a customer standing in front of you, cut it. Plain, warm, specific language outsells adjectives every time.