The most common sealed lead acid batteries (SLA) use blade connectors. These are a single wire connection using a flat ‘blade’ which is inserted into a receptacle. Usually, both the connector and receptacle have wires attached through soldering or crimping. Sometimes, pushing the receptacle onto the blade forms a connection.
These connectors come in two sizes: F1 and F2. F2 terminals are slightly wider than F1 terminals. There are terminal clips available to convert an F1 terminal into an F2.
Here are some comparison images (enlarged for clarity) showing the sizes of the terminals:
F1 Terminal – 3/16″ (0.187″, 4.8mm) wide
F2 Terminal – 1/4″ (0.25″, 6.35mm) wide