The cartridge on the left is the DENON DL-102SD, designed for playing
standard 78 RPM records.
On the right is the DL-102.
Both cartridges can be attached to a modern head shell.
The DL-102 cartrige is used by AM radio stations.
The DL-102 is not for mono LP's nor is it for 78 RPM records.
Instead, the DL-102 is specially designed to output a mono signal from a stereo LP, so there is no danger of damaging a modern LP by its use.
DENON recommends three gram as the best tracing force for DL-102.