n05240 Simpson 0 to 50  ac amperes  155md  0-50/5 aca 2.5 inch round co-013002-007np  serial # aj0471142502 spe ail

the n specs are based off of part#02140, see datasheet.

n05240 is model 155, 0-5aca input with dial reading 0-50 ac amperes

745918653930