The tip barrel is required to be able to continue using tips of the series TIP PT... ET... (one-part tips) with the current versions of the soldering irons LR-21 or TCP. For current soldering irons (LR-21, TCP) Weller has 2-part tips with a smaller diameter. Therefore the hole diameter of the current sleeves is also smaller, so that the "old" tips can no longer be used. https://elecena.pl/product/18589923/t0051031199-tip-sleeve-with-nut-for-weller-lr-21-and-tcp 2021-05-27 https://elecena.pl/product/18589923/t0051031199-tip-sleeve-with-nut-for-weller-lr-21-and-tcp 2022-03-18 https://elecena.pl/product/18589923/t0051031199-tip-sleeve-with-nut-for-weller-lr-21-and-tcp 2022-05-29 https://elecena.pl/product/18589923/t0051031199-tip-sleeve-with-nut-for-weller-lr-21-and-tcp 2023-05-15 https://elecena.pl/product/18589923/t0051031199-tip-sleeve-with-nut-for-weller-lr-21-and-tcp 2024-01-19 https://elecena.pl/product/18589923/t0051031199-tip-sleeve-with-nut-for-weller-lr-21-and-tcp 2025-04-02 https://elecena.pl/product/18589923/t0051031199-tip-sleeve-with-nut-for-weller-lr-21-and-tcp 2026-04-03