This is the 962nd most frequent Russian word.
специальных
"Special" or "specialized."
The word 'специальных' pertains to tools that are specifically designed or designated for a particular task.
У нас есть набор специальных инструментов для ремонта.
We have a set of special tools for repairs.
The word 'специальных' in this context refers to groups that are specifically formed for a certain purpose, perhaps tailored to skills or interest levels.
Спортивный клуб предлагает тренировки в специальных группах.
The sports club offers training in special groups.
The word 'специальных' here refers to sources that are specialized or dedicated to a specific field of study or interest.