The great thing about the weights is that you can put them in or take them out as desired. You can add more weights to the back of the first weights and adjust to about any weight for perfect arrow flight.
The weights are threaded and have a hex head to allow the use of the wrench.
Gold Tip has a 3' allen wrench that allows you to go in thru the nock end of the shaft, no need to remove inserts (risk damaging shaft) to add or remove weights.
The old GT system required you to remove the insert to add or remove weights. This new system using the long wrench is very easy to use.
Most of the 100 gr brass inserts are not threaded for the weights, but the standard GT inserts are threaded for the weights.