if any one has used them or is curently useing them can you tell me what they are like?

you can get the fror the front or rear tire and they are ment to simulate the tire presure with out haveing any issues with nails or getting a flat tire and any one tell me if they are any good thanks for any help u can give mark

Can you get them at trials "pressures" ?

For trials? Won't work (I don't think).

For enduros, good but odd. The simulate quite low pressures, they tyre wanders a bit. Sort of like you have a puncture. Ditto, a square hit will feel like you have a puncture.

has any one tried them on a trials bike?

Ohhhh a mousse...wondered what we were on about in this thread!!

I fitted a set to a trials tyre on my DRZ for an enduro that stipulated trials tyres. It felt ok but I estimate the pressure to be equivalent to 12psi.

And my goodness they were hard to fit!

ok so probly a bit hard for trials then