Weight Disk: Spark Disk
Wide Survivor with two additional lighter flints and some adhesive sandpaper strips as optional addons (they do not come pre-applied, but as a sticker sheet). These are generic Zippo-style lighter flints and adhesive paper-backed 120 grit silicon carbide sandpaper in strips, nothing bespoke. Came in a two-pack, as they only spark with each other.
Flints add a little recoil, sandpaper reduces recoil recoil slightly, adding grip for spin stealing, but can damage opposing Beyblade parts.
Sandpaper assists very marginally in spin stealing, but LAD is in the end more important, so the impact is minimal at best. Nonetheless, sandpaper and no flint is the best configuration.
The impact is probably not worth damaging other Beyblades (don't be a jerk), and as such it is best to stick to Wide Survivor - you're not going to win or lose over the difference.
With Sandpaper and Flint, generally Wide Survivor is the better part due to slightly lower recoil. With only sandpaper, it is marginally at best better than Wide Survivor, with the downside of being generally rude to use sandpaper against opponents Beyblades.
Overall, competitive even with the flints, but it's probably better to just take the extras off and stick to Wide Survivor, or even better, to go with Wide Defense.
Releases including this part
#12 Spark Disk (Two Pack of Wide Survivors plus optional flints and spark paper for conversion.)
Prototype Spark Disk
Prototype design shown in Spin Up Book Vol 1, this version was not released, however.