The black Aesculap GTA138 is a 32 mm stainless-steel clip-on comb for compatible SnapOn blade sets. It is the tallest individual attachment listed in this manufacturer's standard SnapOn comb range, making it a useful option when greater shearing height is required. Aesculap specifies use with blade sets GT317, GT326, GT330 and GT333.

The comb's stainless-steel tines are designed to hold their shape and pass through fur while helping create a uniform cut. A clip-on fitting allows attachment changes, and the black color code identifies this 32 mm size within a collection of combs. The listing is for one attachment, suitable for adding this particular height or replacing the corresponding comb in an existing kit.

Allow for the underlying blade when determining the finished length. Following Aesculap's published method, the comb height and blade cutting length are added together. A GTA138 fitted over a 1.5 mm GT330 blade therefore gives a nominal combined length of 33.5 mm. The 32 mm designation is the attachment's height, so it should not be treated as the total cutting length of every compatible combination.