View Source BlueHeron.ATT.ReadBlobRequest (blue_heron v0.5.0)
The ATT_READ_BLOB_REQ PDU is used to request the server to read part of the value of an attribute at a given offset and return a specific part of the value in an ATT_READ_BLOB_RSP PDU.
Bluetooth Spec v5.2, vol 3, Part F, 3.4.4.5