Triumph Closed-End Layshaft Needle Roller Bearing (1) 57-1606 - T100 / 6T / T120 / TR6 Lucas This is the Black Button

This is the Black Button type which is "Normally Open"

Check your parts book and the specifications abouve

M Part number is 82-4361 or F4361

M Part number is 70-3863 or E3863

Triumph Closed-End Layshaft Needle Roller Bearing (1) 57-1606 - T100 / 6T / T120 / TR6 Lucas This is the Black ButtonNew! USA Made Triumph Closed End Layshaft Needle Bearing. These new Koyo Torrington bearings are the highest quality needle bearings you can install in your Triumph! Made right here in the USA! Fits all Triumph 650 & 750 Unit models (Bonneville, TR6, T120TT, T120C, T140, TR7, Tiger, TR6C & Trophy) from 1963 1983. Fits Triumph 350 & 500 Unit models (T100, T100A, T100R, T100SS, T100C & TR5) from 1961 1974. Also fits many Triumph & BSA Rocket III Trident