I've had a 'Bergen' set for some years now and found them to be of good quality,they are a flexible head at both ends and can get into really awkward places.
I have managed to strip the 'often used' 10mm gears,and haven't come across a replacement yet,they tend to come in sets.
Wish I'd used a ring spanner to slacken it first.
Ken.
https://www.ebay.co.uk/itm/Bergen-6-...tXc:rk:20:pf:0