backcheck door closer and the N8824 power selectable from size 2-4 door closer.
Flexible 8 channel metering includes selectable ballistics, clip and limiting indicators.
There are five analog bass management inputs with selectable crossover for 5.1 surround sound production.
Most thermal vision goggles or binoculars are fairly compact for ease of use and also offer adjustable focus and selectable polarity.
Instead of travelling through a "story" mode, all of the missions -- if you can call them that -- are selectable right from the start, each technically no more difficult than the next.