It is still functional but there are quite a bit of dirt and rust on the inner side as dirts always build up from there.
DCD Chain Device, Retro MTB, Vintage, Daves Chain Device
Dave's Chain Device DCD Mr Crud Bike Chain Tensioner Retro MTB Rare Red
DCD Mr. Crud chain Device
RSP Downhill MTB Bike Chain Device 32-38T Chain Retention Device ISCG-05 Alloy
RSP Downhill MTB Bike Chain Device 32-38T Chain Retention Device ISCG-05 sku0216
