SKS stands for "Same Key System." These types of cores enable you to lock all your Yakima products with just one key. When replacing a core on your Yakima product, you may need a Control key to remove your existing unlocked core so you can transfer the core to a different Yakima product.
This item gets you a single lock core.
Note: Some products require multiple lock cores to take full advantage of locking functionality, consult your product manual for more details.