I find the C33H-6-4R Starrett Combi Square to be a miracle of workmanship. The 90 and 45 degree angles are checked precisely. on the head was pristine The slide mechanism was smooth as silk - no binding or rough edges The blade's matte chrome finish eliminates glare and makes the blackened numerals and lines easy to read in all lighting conditions Don't be afraid to lose it I can only recommend this premium square highly recommend.