This is a Rapax Modular 2.8 joule spring, which includes a fps adjuster ring for added modularity as well! This fits most bolt action platforms as it is a 13mm spring.
Modular Compatibility
Can be used in Tokyo Marui VSR-10, Silverback SRS/TAC41, Well L96, Novritsch SSG10, SSG96, etc. Since it has a 13mm inner diameter it has compatibility with all the above mentioned sniper rifle replicas! A spring guide compatible with 13mm springs is needed.
