This kit includes the additional items needed to apply your prosthetic. Included in the kit is spirit gum (with brush), spirit gum remover, castor sealer (with brush), and clear liquid latex (with brush).
The castor sealer seals the latex prosthetic. You brush the castor sealer on using the included brush built into the lid to coat the entire prosthetic and let set. This prevents oils used in makeup and makeup removers from breaking down the latex and increasing the life of your prosthetic.
Spirit gum is the easiest and most popular way of applying prosthetics. To do this you first dry fit the prosthetic to get an idea of where the attachment points will be. You will then apply spirit gum using the brush included in the lid to the prosthetic piece at the points where it meets the skin and then let it set out for a bit to "cure". While you are waiting for that you will want to brush on spirit gum to the skin where the prosthetics will sit and tap it with your fingers a few times to increase the tackiness of the spirit gum. Now bring the two together.
Finally using the brush included with the clear liquid latex blend the edges of the prosthetic piece to create a seamless look between the prosthetic and your skin. Apply makeup, additional prosthetics, and blood and gore effects to suite your liking.