Aye Dave,
Red rubber grease, about £10-00 + VAT for 500g tin, from motor factors. If none available, a wee touchy Oregon, liquid red grease, used to lubricate the rollers in the nose sprocket of chain saw bars. Not sloppy but hasn't the stickiness of ordinary grease, which can cause problems. Good stuff as well for putting beneath the cams etc. when assembling the engine, doesn't run down faces/drip. Comes in 1 litre plastic bottle. Most horticultural machine or arboricultural suppliers who deal with chainsaws. Price? Not known.
Regards, Bill.