An example, using the sg_inq command from the sg3-utils package:
[choo@simey ~]# sg_inq /dev/sg0
standard INQUIRY:
PQual=0 Device_type=5 RMB=1 version=0x02 [SCSI-2]
[AERC=0] [TrmTsk=0] NormACA=0 HiSUP=0 Resp_data_format=2
SCCS=0 ACC=0 TGPS=0 3PC=0 Protect=0 BQue=0
EncServ=0 MultiP=0 [MChngr=0] [ACKREQQ=0] Addr16=0
[RelAdr=0] WBus16=0 Sync=1 Linked=0 [TranDis=0] CmdQue=0
length=44 (0x2c) Peripheral device type: cd/dvd
Vendor identification: YAMAHA
Product identification: CRW-F1E
Product revision level: 1.0c