LEGO 4216 Basic Building Set, 3+ Instructions, Basic
LEGO Part 4216 Brick, Modified 1 x 2 with Groove (Lime) | iBricktoys: LEGO shop guide and database
BrickLink - Part 4216 : LEGO Brick, Modified 1 x 2 with Groove [Brick, Modified] - BrickLink Reference Catalog
Amazon.com: Eske Kouri Gobricks GDS-798 Brick 1X2 W. GROOVE-1x2 Brick with Vertical Groove Compatible with Lego 4216 All Major Brick Brands,Building Blocks ,Technical Parts ,Assembles (106 Orange(021),30 PCS) : Toys & Games
LEGO Red Brick 1 x 2 with Groove (4216) | Brick Owl - LEGO Marketplace