The Extended Vise Grip Locks are extended bolt versions of the original locks. They are only necessary if you have thick walls, thick door jambs, and/or thick trim.
Measure First Before You Order
You need these only if the measurement from your door jamb (the ridge against which your door closes) to your outer trim is between 4 3/4″ and 6 3/4″ inches or from 12-17 cm. They come in sets of two so ordering one of these items in your cart will result in 2 being delivered, one for each side of your Gorilla Gym core unit.
If the distance is greater than 6 3/4″, then the Gorilla Gym will not fit securely in that doorway at this time.
Watch this video for more information and how to measure: http://youtu.be/WcUPpUv0dSk