Review on 600-Piece White Zip Ties Assorted Sizes - Standard Self-Locking Nylon Cable Tie Set with Cable Mount - Ideal for Wire Management, Home Office, Garage Strip Fastening - 4/6/8/10/12 Inch by Joel Miranda

Made of cheap, non-durable plastic. I've never had a cable break unless I used extreme force and even then it was very tough. They snap on you almost immediately as soon as you attach and pull them. I don't like writing reviews, but if I feel like I've just been fooled by a cheap product that's trying to pass off as durable, then I have to say something. I'll send it back immediately.