IRWIN Marking Flags, 2.5-Inch x 3.5-Inch x 21-Inch, Blue, 100-Pack (2034206)

Used these to mark out a road, some fence lines and a 'guide' area in a field on a very windy and wet site. Easy to push into 3"soil and then shale. Held firm, all 100 of them. Never bent when pushing in. Rusty patina when left over night, not structural loss. Cleaned and dried them, added WD40 and wrapped them in cling film on storage. Yellow showed well on green-to-yellowing grass on a dull grey day. Nice if there were some white ones too (10%?) for key points. Flapped well in wind. held shape. A sheep pulled one from the ground, had a chew, spat it back out. None others touched. That one was fine to use again. None of the flags left the wire. All intact.

Rusted in no time at all and the flimiest metal you could imagine.