Can family members send things to the detention center?
If it is the investigation stage, you can only entrust a lawyer to meet with you. If you need to send something, you can send it through the lawyer. If it is the review and prosecution stage, you can entrust a defender, not just a lawyer, to send relevant items. Generally, detention centers can only send clothing and daily necessities, but are not allowed to send food. Letters also need to be inspected before they can be passed.
Defense lawyers can meet and communicate with criminal suspects and defendants in custody. Other defenders may also meet with and communicate with criminal suspects or defendants in custody with the permission of the People's Court or People's Procuratorate.