We have decided to allow people to pre-order the Operator System, the people who pre-order this item will wait for the product until release but will receive a cheaper deal on the product. We will be only allowing 20 people to pre-order this product so not everybody can just pre-order it now. This will allow us to work more to add some finishing touches to the Operator System since we will already have feedback on the product. This product works with all gun kits that can hold tools, e.g. ACS Gun kit, FE Viewmodel, Roblox Battle Royale Gun Kit. They are not the only supported ones but we are just naming the largest used gun kits. If you have any questions about the gun kits message the owner