Upgraded Kit For SRB Series

With the accessories FXT WORKS provided, enjoy reliable performance at 250-270 fps & 13 shots/sec for the SRB400 / SRB400-SUB / SRB1200 / SRB375M / SRB1300.

This bundle will include these：

• Unequal Spring * 1
• 7.4V 2000mAh High-rate Discharge Li-ion Battery *1
• Gel Balls * 10,000

How to upgrade

Use a screwdriver to disassemble the gun body casing, rotate the button at the back of the gearbox, remove the original spring, and replace it with a new one. Upgrading the firing rate is effortless!