R-Hop modification kit made by Italian company Psionic Upgrades.

Kit components:

-Smooth Hop Up rubber band with sealing rings

-Two concave spacers

-Two strips of tape for mounting the kit without glue

Kit features

- Easy mounting requiring no glue or barrel modification

- Large working range, from 0.8J to 1.5J

- Proprietary manufacturing material, no silicone admixture.

- Temperature resistance to -10°C

- Higher abrasion resistance

- High flexibility and fit to the barrel (better sealing)

- Increased friction compared to silicone, increased ball curl.