When deciding on the best fully insulated female spade connector, you should think about the wire size (mm or AWG) as well as the tab size that it will be connected. The width from the receptacle should match the width in the tab, and the thickness from the tabs can vary. Common tab sizes include .110 (2.8mm), .187 (4.8mm), .205 (5.2mm), .250 (6.3mm), and .375 (9.5mm). Proper selection ensures a good and reliable electrical connection.