Phonics PebblesIdeal for introducing letters and their sounds, these tactile pebbles are durable for use in sand, water and small world play, indoors and out. Cast from a unique resin and stone mix, each pebble is engraved with a grapheme and measures 30 45mm. The set contains 54 pebbles covering the 44 phonemes from phases Two and Three of Letters and Sounds, plus the most common alternative spellings from phase Five.