****o this is Beth from Dremel. The bits that you have purchased are "Trio Tool Bits", which is our special rotary tool (with a pivoting handle), that uses it's own size of bits. These are 3/16" shank sizes and can ONLY be used with this model 6800 Trio. Any bits that you see that begin with the letters "TR", is an indication that these are for the Trio tool. For your tool, we do make MANY router bits, these you can view on our website at www.dremel.com
. Just go to the "accessory" tab and select the "High Speed Rotary Tool", and then select "Routing". If you have any further questions, please feel free as well to call our Dremel Customer Service Representatives on our toll free number of 1-800-437-3635, Monday-Friday, 8:00 am - 6:00 pm, CST. Any of us would be happy to assist you!
-Beth at Dremel