Most people think of recorders as coming in a couple of sizes.  Soprano and alto are the most common.  As with other woodwind instruments, there is a whole family of recorders.  Typically they alternate between the keys of C and F (sopranino in F, soprano in C, alto in F, etc).  Recorders also come in more obscure keys.....sopranos in Bb and A, altos in G, tenors in D.  I've recently picked up a tenor in D (AKA voice flute).

It is branded "Peter Harlan Markneukirchen".  Peter Harlan is credited with developing the German system recorder.  He wasn't really a wind instrument maker (I think I read he did make some, though), and hired various other instrument makers in Markneukirchen, Germany to make his recorders.  Most of these were made by Martin Kehr.  This one is made from beautifully striped rosewood and is the German fingering system typical of Peter Harlan instruments.  

Below are pics of the tenor in D, plus some comparison pics of other recorders.  I've got one other Peter Harlan instrument, also in an unusual key.  It's a soprano in A.