If you need a sample, maybe you can buy it from here: http://www.aliexpress.com , we have some agents on AliExpress.
You can search text “SL04 DMX box” on AliExpress find SL04 box.
or find SL04 box by searching “MA3 DMX512” text on Taobao.com.
Contact me:
WeChat: hahan4567
Email: 1195722899@qq.com
Thanks！