LEGO PART 553B LIGHT TAN 2 x 2 ROUND BRICK DOME TOP x 4 | eBay
LEGO Part 553b Brick, Round 2 x 2 Dome Top - Blocked Open Stud with Bottom Axle Holder x Shape + Orientation [Tan] (4162726, 4216648, 4519911) | iBricktoys: LEGO shop guide and database
BrickLink - Part 553b : LEGO Brick, Round 2 x 2 Dome Top - Blocked Open Stud with Bottom Axle Holder x Shape + Orientation [Brick, Round] - BrickLink Reference Catalog
LEGO Part 553b Brick, Round 2 x 2 Dome Top - Blocked Open Stud with Bottom Axle Holder x Shape + Orientation [White] (4216652, 4124120) | iBricktoys: LEGO shop guide and database