In general, 10Gb SFP (Small Form-Factor Pluggable) modules are designed to operate at the specified data rate of 10 gigabits per second (Gbps). However, many 10Gb SFP modules are backward compatible and can operate at lower data rates, including 1 gigabit per second (Gbps).

If a 10Gb SFP module supports 1Gb operation, it is often referred to as a "1/10Gb" or "1/10" module. This means that the module can be used in either a 1Gb or 10Gb port. The backward compatibility is often implemented to provide flexibility and allow for gradual upgrades in network infrastructure.

It's important to check the specifications and documentation of the specific 10Gb SFP module you have to confirm its compatibility with 1Gb operation. If it is a 1/10Gb module, it should work in a 1Gb SFP port without issues. Keep in mind that the network equipment (switches, routers, etc.) must also support the lower data rate for proper operation.