It is not necessary to add the Tara small 10X mirror (https://fancii.com/products/tara) when purchasing the Abigail 10X (https://fancii.com/products/abigail-10x), as the countertop Abigail 10X mirror already provides 10X magnification.
However, the Tara small 10X mirror serves as a convenient, fully magnifying accessory that can be easily attached or suctioned onto various surfaces such as other mirrors (regular view without magnification such as the Abigail 1X mirror model - https://fancii.com/products/abigail-travel-mirror), ceramic, marble, acrylic, porcelain, or enamel. It is an excellent compact addition for use on bathroom mirrors or any smooth surface where a portable, magnified view is beneficial.
The dimensions of the Tara are approximately 3.5 inches (9 cm) in diameter.