Making a mailbox delivery alert using coat hanger wire

Inspired by this gadget, I’m attempting to replicate the functionality using a coat hanger wire bent in a similar fashion.

https://www.amazon.com/dp/B00IEDYWTK/ref=cm_sw_r_em_api_glt_i_19E6XASD1PFVAHMS9QX4

Here's what I did:

1. Took a coat hangar, cut the wire and curled one end in a spiral (I wrapped it around a pencil, metal mandrel would have been better) to act as the lever (the part that makes contact with the front of the mailbox). Shaped the hangar more or less to mimic the commercial gadget in length, bending the angled end at about 50 degrees.
2. Made a large loop at the bend and worked it into the cavity in the small caster wheel
3. Used magnets to hold the caster wheel and the stop (just a corner bracket adhered with caulk to the magnet) against the side of the mailbox.
4. Attached a marker flag with zip ties to the hangar.
5. Positioned caster wheel about 1.5" from bottom and 2" from front.

Voila. It works!