deluxe large 4" wood frog guiro rasp - percussion musical instrument tone block - by world percussion usa world percussion usa the world percussion usa brand 4" natural frog guiro is better than other frog instruments because of the construction, finish, and sound. the standard medium 4"x4" size creates a ribbit-like, croaking frog sound when played correctly. it also an alto-range pitch as a wood tone block. instructions: use the wood stick (included) to gently rake up the frogs back to create a lower-pitch cricket chirp. or lightly tap the nose of the frog with a thick end of the striker to get a deep resonating note as a wood tone block. store the striker in the frog's mouth. note: this 4" size frog guiro is large enough to be safe for children and strong enough to hold up to the rough handling of children, but it is not a toy. recommended age 12+.