Aesculap Clip-on Comb or  SnapOn guard combs are well made sturdy with metal teeth that slide effortlessly through hair. 
• for SnapOn clipping heads 3/8, 1/2" , 5/8", 
• optimum and uniform cutting results
• easy to set for various cutting lengths
• glides easily through fur
• easy and quick to clip on

sold in singles by size

GT133-13 mm or 1/2"
GT134-16 mm5/8"
GT135-19 mm3/4 "
GT136-22 mm 7/8"
GT137-25 mm 1"

* these are well made, more sturdy and stay put better than Wahl.