Montessori Phonics Initial Sound Cards are designed to facilitate the process of learning to read as an addition to Montessori Language materials:
Sandpaper Letters
Moveable Alphabet (affiliate links)
Each card measures approximately 6×6 cm or 2.4 x 2.4 inches.
This is an updated version that contains all cards with the pink border PLUS vowels with the blue border.
Please note that these cards are also available with the back border and without border: