This is the 10-hole version of the standard #270 Chromonica (without the two highest holes). It is hard to beat the quality and price of this harmonica. The #260 is closer in size to a diatonic which makes hand effects a bit easier and this harmonica is very airtight for better volume and tone. Key of “C”, 10 holes, 2 1/2 octaves, hole 1 is “middle C”. Comes in aprotective plastic case.