Used on ATCRBS. formed steel ring measuring 5.250inches o.d.; 3.281" i.d.; length 1.000"; outside periphery grooved 0.125"; first end 0.281" thick; 4.093" 0.d.; surface width 0.375"; contains 2 bolt holes 0.250" in diameter; second end is 0.562" thick; surface width 0.093