Your SteadyGroover is in solid beech wood.
Oiled for a natural finishing.
It come with two 40 mm suction cups to stick to your guitar.
But take care :
A SteadyGroover will well stick if your guitar is finished with a glossy varnish.
If you have satin varnish it will less stick.
And if the varnish is damaged it may not stick at all.