Bosch 1-7/8-in Carbide-tipped Tongue and Groove Router Bit in the Cabinetry & Joinery Router Bits department at Lowes.com
YONICO Tongue and Groove Router Bits Set Up to 3/4-Inch Stock 1/2" Cutting Depth 2 Bit Set 1/4-Inch Shank for Edge-to-Edge Hardwood Flooring, Paneling, Cabinet Door, Plywood Sheathing 15221q - Amazon.com
Flooring 2 Bit Tongue & Groove V Notch Router Bit Set -1/2" Shank - Yonico 15230 | eBay