Vintage Guidecraft Sound Boxes teaching tools with matching wooden cubes

Description

I bought these vintage Guidecraft Sound Cubes new for my daughter who has autism.
I've had them for about twenty years. The cubes are in fantastic condition as they were not used that much. The tray they sit in has some splits in the wood. (Please see the pictures.) They come in the original box, which shows some shelf wear.
Children shake the wooden cubes to hear each unique rattling sound and then find its match.
This set of 12 has six pairs of matching cubes to help in sound discrimination. The color-coded dots on the bottom can be compared for self-correction.
They help develop children's ability to perceive sounds, which builds concentration, matching, and focusing skills.
Guidecraft stopped making these teaching tools to the best of my knowledge, but I don't know how long ago.
From what I can tell the wood is pine.
They are great for pre-K+ or special education or persons with developmental disabilities.
Please look at the pictures carefully, for they are a part of the description. If you have any questions, please ask them before bidding or buying because these sound cubes are not returnable.
I ship within three business days, using recycled materials whenever possible.
Please buy or bid only if you can make payment within three days of purchase.
Thank you for looking.