You may not need extenders as the Vise-Grips are designed to grab only from the doorstop ridge (the raised piece that your door closes against) to the front side of your door trim—not the entire side of your doorway!
The Extended Vise Grip Locks are extended bolt versions of the stock 3-prong bolts that came with your vise-grip package. The Extenders are only necessary if you have thick trim, thick door jambs, and the included stock vise-grip extenders are too short to grab from your doorstop ridge to the outer trim. There are two extender sizes depending on your specific doorway measurements but only one size will work–don’t order the largest thinking it will size down–each extender size only works for those specific measurements. Very very few doorways require the longest (super) lock extenders (6 3/4 to 8 3/4 inches) so make sure you order the one that will work for your doorway–usually the 4 3/4 to 6 3/4 inches lock extender size.
Measure Twice Order Once! (Warning: DO NOT MEASURE FROM ONE SIDE of the TRIM to the other side of the doorway TRIM)
You need the regular extender only if the measurement from your doorstop ridge (the ridge against which your door closes) to your outer trim is between 4 3/4″ and 6 3/4″ inches (12-17 cm) OR if the measurement is 6 3/4″ to 8 3/4″ inches (17cm – 22cm) for the super extender. Easiest way to measure is to close your door, measure from that point forward to the front trim–that is the measurement that matters. Extenders come in sets of two so ordering one of these extenders in your cart will result in 2 being delivered, one for each side of your Gym1 core doorway unit.
Choose the correct Extender size for your trim thickness from the drop-down menu. Note again that very very few doorway trim situations ever require the super extenders which fit the 6 3/4 to 8 3/4 gap so please measure carefully only from the doorstop ridge to the front of your trim. Front of the trim is opposite the side of your doorway from where your door swings out–so again, just close your door and measure from that point forward to the front of your trim. If you order the super extenders, they cannot size down to fit below 6 3/4 inch length needed.
If you have any doubts, shoot us a quick email to firstname.lastname@example.org and feel free to include pic(s) or a video about your unique doorway so we can diagnose and advise.
No Door or Door Stop Ridge? In certain situations where your door trim has no door stop ridge because there is no door–then by all means you can have the vise-grips grab from one doorway side of the trim to the other side of the doorway trim–and you might need extenders for that span.