Block from U+1B130 to U+1B16F. This block was introduced in Unicode version 12.0 (2019). It contains 9 codepoints.
The Wikipedia provides the following information on block Small Kana Extension:
Small Kana Extension is a Unicode block containing additional small variants for the Hiragana and Katakana syllabaries, in addition to those in the Hiragana, Katakana and Katakana Phonetic Extensions blocks.