When choosing the right fully insulated female spade connector, you should consider the wire size (mm or AWG) and the tab size to which it will likely be connected. The width of the receptacle should match the width of the tab, and also the thickness from the tabs can vary greatly. Common tab sizes include .110 (2.8mm), .187 (4.8mm), .205 (5.2mm), .250 (6.3mm), and .375 (9.5mm). Proper selection ensures a safe and secure and reliable electrical connection.