What are the manufacturers of heat shrinkable tubes for low voltage cable joints?

In the Pearl River Delta, there are Changyuan Electronics, Wall Nuclear Materials, and Alpine.

In Suzhou, there are more than a dozen, such as Dasheng, Jiuwei, Huading, Boer, etc.

In Wenzhou, there are too many, the well-known ones include Huayi, Yongli, Yonggu, Leite, Nanda, Huapeng, etc.

Huangshi, Hubei, there is a Shenbo, which is also very good

Northeast, mainly in Changchun and Jilin, such as Changchun Yinghua, Xianzhong Heat Shrink, Jifu, etc.