The "standard" Aspect Finder is aligned with the eBay Item Specific mandates that are being rolled out and is currently FREE courtesy of eBay
More information on the specifics around mandates can be found in seller centre on the relevant regions, and eBay are announcing details regularly.
The benefits of adding aspects has been measured and published by ebay;
Dress listings with the item specifics “Style” and “Dress Length” completed, sell 81% more than those without.*
- Report comparing average sales value per listing for listings with item specifics “Dress Length” and “Style” vs those without from December 2017 - July 2018.
Optiseller's Aspect Finder + goes beyond the mandates, and allows users to apply these benefits across a wider range of categories and aspects.
Aspect Finder + is available in out paid-for plans, starting in our Essential plans - https://www.optiseller.com/pricing
Aspect Finder + will allow you to update all of the Item Specifics within the eBay mandated categories, and we are continually reviewing the categories available within the Aspect Finder +
If you find that your category or aspect is not currently available, get in touch and we will add them in for you!