Bought them for my new guitar project ( extreme design guitar for heavy music), so what can I say -- Schaller keeps a mark on a guitar accessories, and these machine heads not an exclusion too. Previously I purchased machine heads from Gotoh ( top-locking variant), and their quality didnt make me satisfied - shafts on a two machine heads 2-d and 3-rd strings to be precise was broken after a year of usage. And I have an another guitar with a Schaller F-Series machine heads ( also top locking variant) which are serving me more than 15 years without any problems and replace. After that, I decided to replace early bought tuners from Gotoh to Schaller, so may recommend them to anyone.
Regards, Viktor