It's for the first 100 people.
Glow In The Park is coming to the east coast for the first time on November 12.
The ultimate night-time 5k is taking place at Meridian Showground, Cleethorpes, in aid of Andy's at St Andrew's Hospice.
If you haven't yet registered, here's a chance to get 20% off individual or group registrations.
Use the discount code 20%OFFCT at www.glowinthepark.co.uk, but hurry, it's for the first 100 people only... Happy glowing!