These are two robot arms with missle launchers, fully compatible with Warhammer 40k Dreadnought models. The models includes two left arms. One with a Deathwatch insigna and one with the Salamanders insignia.
When you recieve the arms they are connected with small sprues. Cut or clip off these with a model knife or a pair of pliers. The arms can easily be magnetized with a 5 mm diameter wide and 1mm thick neodym magnet.
v1.1 Reinforced sprues to increase structural integrity
White strong & flexible is the simplest material, all details will be fully visibel. The material has slightly rough surface. I recomend brushing of any excess powder with a thick brush and use a primer to create a good adhesion before you paint them.
Frosted detail is the optimal material and will end up with a smooth surface and crisp details. There might be an oily coating on the model after printing. Please wash the model in water with some soap or mild detergent before priming.
See also my Dreadnought autocannon arms
and Customizable Dreadnought Missile launcher arms