Whistles for Thelma are almost all sold out.

The Amalgamated Transit Union Local 1505, which represents Winnipeg Transit Drivers, is partnering with their health and wellness committee to sell safety whistles in the search for missing 57-year-old Thelma Krull.

Union president John Callahan says the $10 whistles were supposed to be available by Wednesday, but due to a delivery delay, will now be available early next week.

The keychain-style whistles are yellow and say “Whistle for Thelma” on them. They also have an LED light.

Pre-orders are being accepted.

Profits from their sale will add to the $5,000 reward the union is offering for the safe return of Thelma Krull.

Thelma's husband Robert is a member of the Transit Union.

The whistles can be ordered by calling the Transit Health and Wellness at 204-986-7909 or the ATU at 204-943-5064.

The friends and family are also asking everyone to wear purple Wednesday, July 22.

Wear it Purple posters have been posted on Facebook and say to use #purple4Thelma on social media.