There are several types of crystal head models.

　　The types of crystal heads are diverse, and according to different standards and uses, they can be classified in the following ways:

　　Classification according to interface standards

　　RJ45 crystal head

　　Features: With 8 grooves and 8 touchpoints (8p8c), it is the network interface standard.

　　Applications: Widely used in Ethernet, Fast Ethernet, Gigabit Ethernet and other network environments to connect computers and network devices (such as network interface cards, hubs, switches, etc.).

　　RJ11 crystal head

　　Features: Only 4 pins, but usually refers to a modular jack or plug with 6 positions (6 pins), of which only 4 pins are used, which is the standard for telephone interfaces.

　　Application: Mainly used for telephone line connection, such as connecting phones or modems. The RJ11 crystal head can usually be inserted into the RJ45 interface, but not vice versa.

　　RJ12 crystal head

　　Features: Usually also suitable for voice communication, but with six pins (6p6c), there are also two types of six-slot four-pin (6p4c) and six-slot two-pin (6p2c).

　　Application: Mainly used for voice communication.

　　Classification by supported Ethernet categories

　　The models of crystal heads also typically correspond to the Ethernet categories they support. Here are some common models:

　　Cat 3: Type III, supports a transfer rate of 10 Mbps, suitable for early telephone networks.

　　Cat 5: Category 5, supports 100 Mbps transfer rates for Fast Ethernet.

　　Cat 5e: Enhanced Category 5, supports 1000 Mbps transfer rates for Gigabit Ethernet.

　　Cat 6: Category 6, supports 1000 Mbps transfer rates but outperforms Cat 5E, suitable for Gigabit Ethernet. Common six types of crystal heads are non-screen integrated, non-screen split, shielding integrated, shielding split, etc.

　　Cat 6a: Enhanced Category 6, supports 10 Gbps transfer rates for 10 Gigabit Ethernet.

　　Cat 7: Category 7, supports a tranSMission rate of 10 Gbps, but it uses shielded cables to reduce electromagnetic interference compared to Cat 6a.

　　Cat 7a: Enhanced Category 7, supports 10 Gbps transfer rates, uses shielded cables, and is suitable for 10 Gigabit Ethernet.

　　Cat 8: Category 8, supports 25 Gbps and 40 Gbps transfer rates for higher speed network applications.

　　III. Differentiation methods

    Observe the number of pins: RJ45 crystal plugs have 8 pins, while RJ11 crystal plugs have only 4 pins (although the shell may have 6 positions).

    Understand the interface standard: RJ45 represents the network interface standard, while RJ11 represents the telephone interface standard.

    Check the size: RJ45 crystal plugs are usually larger than RJ11 crystal plugs with only 4 contacts due to their 8 grooves and 8 contacts.

    Determine the application scenario: RJ45 crystal plugs are mainly used for network connections, while RJ11 crystal plugs are mainly used for telephone line connections.

    Check the packaging and labeling: Regular crystal plug products usually have clear packaging and labeling, including brand, model, interface standard and other information, which can be used to further confirm the type of crystal plug.

　　Overall, there are various types of crystal heads, and the choice needs to be based on the specific network environment and transmission requirements to determine the appropriate type.