This is somewhat a update for other stick extensions. This time I made a mould that goes around the stick to cast the rubber directly on the stick. This removes any problems with the fit and makes sure it stays on firm. If hesitant on the longevity then add some superglue to lock it down on the stick. Casting is made from two component mould silicone, but any similar rubber or silicone substance can be used. I poured silicone to both mould sides and then put them together over the upside down PS4 controller stick. Stick creates enough overflow in the mould to get perfect model without air gaps in it. Use a clamp to hold mould sides together during curing time.