IR-hop Z-kit from HS Armory. The R-hop variants are the ultimate hopup system, not only greatly increasing accuracy, but also range at the same velocities.. These patches distribute the pressure on the BB better than any other system available including flat-hops and any after market bucking. The IR-hop (Ice R-Hop) is more stable/consistent between warm and cold temperatures. Contains three patches of different depths so the best size can be chosen for the barrel window size which eliminates much of the tuning required in non Z-kit versions.
This is an excellent option for the first time R-Hop installer!