Replace original pull bolt and change to pull-back sniper type bolt.Which make blaster load easier. We recommend modify with 9kg spring.14kg upgarde spring too power which may deform the bolt. Manufacturered by WORKER. Suitable for people over 14 years oldbecause the installation of this product requires some disassembly capacity.All the parts are separate and you need to reassemble them. Blaster not included. Compatible with Longshot CS-6 / LONGSHOT CS-12/ Worker Terminator.