I took over dad's Bosch router in 2008. The half inch collet was missing. Wanting a 1/2" collet started doing a thorough online search, none available. even called Bosch, nada.  This is a good source, will add to my phone contacts. 

Was looking through the stuff DW and I brought home found the 1/2" collet. Made me very happy.  

daveg, SW Washington & AZ