xtra slotENG: Hey guys, in this video I'm bringing the Extra Slot Mhty mod to Sonic 3 A.I.R, the links to the mods used in this video are here in the description. H...Ideal for retrofit applications, over an existing slot; Available in a range of combinations to suit different acoustic specifications; Fits over a Trimvent Select, Trimvent 4000 Hi Lift or Trimvent