While Spark bindings are made SUPER solid, their description of why you need this product below is pretty spot on. It's better to have it and not need it, then to need it and not have it. Get some spare parts and save yourself a suffer fest out of the backcountry.
Manufacturer Description:
Weight: 6.2oz/ea (178g)
2x M6x16mm M's Heel Loop Screws
1x M6x12mm W's Heel Loop Screw
2x M6x10mm Touring Bracket Screws
1x Pillow Line Strap Ankle Adjuster Screw
1x Pillow Line Strap Toe Adjuster Screw
1x Ankle Buckle Screw
1x Toe Buckle Screw
2x Ankle Strap Screws
2x Ankle Strap T-nuts
2x Ankle Strap Washers
1x Snap Block
1x Toe Ladder
1x Toe Adjuster
1x Ankle Ladder
1x Ankle Adjuster
1x Ankle Buckle
1x Toe Buckle